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Virginia SOL Mathematics Textbook

Grade 7 Workbook — Chapter 14: Quadrilaterals and Their Properties

SOL 7.MG.3 · Companion to Textbook Chapter 14

Each page below is one Canva page. Headings are sized for direct paste: page title as H1, section labels as H2. Figures referenced by filename live in ../figures/. Item numbers match the textbook exactly.


PAGE 1 — Chapter opener

Chapter 14 · Quadrilaterals and Their Properties

Standard 7.MG.3

In this chapter you will:

Words to know: quadrilateral · vertex · diagonal · parallel · perpendicular · congruent · line of symmetry · parallelogram · rectangle · rhombus · square · trapezoid · isosceles trapezoid · base · leg · bisect · supplementary · perimeter

How this book defines a trapezoid. A trapezoid has exactly one pair of parallel sides. So no parallelogram is a trapezoid, and no trapezoid is a parallelogram. Use this definition on every page.

Markings decoder. Matching hash marks == congruent segments. Matching arrowheads == parallel sides. A small square in a corner == a right angle.


PAGE 2 — The five named quadrilaterals

14.1 The Five Named Quadrilaterals

FIGURE: fig1-five-quadrilaterals.png (full width)

Complete the property table.

Figure Pairs of parallel sides Right angles Congruent sides
Parallelogram
Rectangle
Square
Rhombus
Isosceles trapezoid

Guided practice.

  1. Parallelogram ABCDABCD.

    Parallel: AB\overline{AB} \parallel ______ and BC\overline{BC} \parallel ______

    Congruent: AB\overline{AB} \cong ______ and BC\overline{BC} \cong ______

  2. Rectangle EFGHEFGH. Number of right angles: ______

    Congruent sides: ______ \cong ______ and ______ \cong ______

  3. Square JKLMJKLM. Three properties you can read from the markings:


  4. Rhombus NPQRNPQR. All four sides congruent? ______ All four angles congruent? ______

    Explain the difference: _______________________________________________

  5. Isosceles trapezoid STUVSTUV. Parallel sides: ______ and ______ Congruent legs: ______ and ______


PAGE 3 — Diagonals

What the Diagonals Tell You

FIGURE: fig3-diagonals.png (full width)

Independent practice.

  1. Write yes (always) or no (not always) in every cell.

    Figure Diagonals bisect each other Diagonals congruent Diagonals perpendicular
    Parallelogram
    Rectangle
    Rhombus
    Square

Do not over-claim. A parallelogram's diagonals bisect each other. They are congruent only if it is a rectangle, and perpendicular only if it is a rhombus.


PAGE 4 — Lines of symmetry

Fold It and Count

FIGURE: fig4-lines-of-symmetry.png (full width)

Draw every line of symmetry. Sketch each figure in the box, then draw each fold line as a dashed line and write the count.

Figure Your sketch with dashed fold lines Number of lines
Square
Rectangle that is not a square
Rhombus that is not a square
Parallelogram that is neither
Isosceles trapezoid

Independent practice, continued.

  1. Lines of symmetry: square ______ · rectangle (not a square) ______ · rhombus (not a square) ______ · parallelogram (neither) ______ · isosceles trapezoid ______

  2. Which of the five named quadrilaterals always have four right angles? ____________________

  3. Which of the five named quadrilaterals always have four congruent sides? ____________________

  4. The diagonals of a rhombus meet at XX. mm\angle at X=X = ______ Property used: ____________________

  5. Application. A window frame meant to be a rectangle has diagonals measuring 6060 in and 6262 in.

    What does this tell the carpenter? _______________________________________________

    Property used: _______________________________________________

  6. Reasoning. Why does a parallelogram that is neither a rectangle nor a rhombus have no lines of symmetry?




PAGE 5 — Exit ticket 14.1

Exit Ticket · Lesson 14.1

Name: ________________________ Date: ____________

  1. Which named quadrilaterals always have perpendicular diagonals? ____________________

  2. Lines of symmetry in a rectangle that is not a square: ______ Where are they? ____________________

  3. True or false: in every parallelogram the diagonals are congruent. ______

    If false, correct it: _______________________________________________

  4. Explain the difference between parallel and congruent, and name a quadrilateral in which both are true of the same pair of sides.




PAGE 6 — The classification hierarchy

14.2 Sorting and Classifying Quadrilaterals

FIGURE: fig2-classification-hierarchy.png (full width)

Complete each sentence.

Every rectangle, rhombus, and square is a ______________.

A square is both a ______________ and a ______________.

A parallelogram is ______ (always / not always) a rectangle.

Under this book's definition, a trapezoid has ______________ one pair of parallel sides, so a parallelogram ______ (is / is not) a trapezoid.

Guided practice. Write T or F and give a reason.

  1. Every square is a rectangle. ______ Reason: ____________________________________

  2. Every rectangle is a square. ______ Reason: ____________________________________

  3. Every rhombus is a parallelogram. ______ Reason: ____________________________________

  4. Is a parallelogram a trapezoid? ______ Reason: ____________________________________

  5. Four congruent sides and four right angles. Most specific name: ____________________


PAGE 7 — Sorting by clues

Give the MOST Specific Name

  1. Fill in the most specific name for each set of clues.

    Clues Most specific name
    a) Opposite sides parallel; four right angles; sides 55, 99, 55, 99
    b) Four congruent sides; no right angles
    c) Exactly one pair of parallel sides; congruent legs
    d) Opposite sides parallel; diagonals bisect but are neither congruent nor perpendicular
  2. Every name that applies to a square. Circle all that apply:

    quadrilateral · parallelogram · rectangle · rhombus · trapezoid

  3. Which figures have exactly two lines of symmetry, and where are those lines?

    ____________________________ Lines: ____________________________

    ____________________________ Lines: ____________________________

  4. Diagonals bisect each other and are perpendicular, but not congruent. Most specific name: ____________________

  5. Diagonals bisect each other and are congruent, but not perpendicular. Most specific name: ____________________


PAGE 8 — Apply and reason

Classification in Context

  1. Application. A floor tile has four congruent sides. Its diagonals cross at a right angle, and one diagonal is longer than the other.

    Most specific name: ____________________

    Which clue rules out "square"? _______________________________________________

  2. Reasoning. Marisol says, "A rhombus is never a rectangle."

    When is she right? _______________________________________________

    When is she wrong? _______________________________________________

    Example for each: _______________________________________________


PAGE 9 — Exit ticket 14.2

Exit Ticket · Lesson 14.2

Name: ________________________ Date: ____________

  1. Four right angles and sides 66, 66, 66, 66. Most specific name: ____________________

  2. Is every parallelogram a rhombus? ______ Counterexample: ____________________

  3. Can a quadrilateral be both a trapezoid and a parallelogram in this book? ______

    Why? _______________________________________________

  4. Why is "most specific name" a fairer question than "what shape is this?"



PAGE 10 — Why 360°360°

14.3 Finding Unknown Angle Measures

FIGURE: fig5-angle-sum-two-triangles.png (full width)

One diagonal splits any quadrilateral into ______ triangles.

Each triangle's angles add to ______°, so the quadrilateral's four angles add to ______°.

FIGURE: fig6-parallelogram-angles.png (full width)

In a parallelogram: opposite angles are ______________ and consecutive angles are ______________ (they add to ______°).

Guided practice.

  1. Quadrilateral WXYZWXYZ: 85°+100°+70°+85° + 100° + 70° + ______ =360°= 360°, so x=x = ______

  2. Parallelogram ABCDABCD with mA=62°m\angle A = 62°.

    x=x = ______ Property: ____________________

    y=y = ______ Property: ____________________

    z=z = ______ Property: ____________________

    Check: ______ ++ ______ ++ ______ ++ ______ =360°= 360°

  3. FIGURE: fig7-unknown-angles.png (full width)

    Isosceles trapezoid PQRSPQRS with mP=63°m\angle P = 63°: n=mS=n = m\angle S = ______ mQ=m\angle Q = ______ mR=m\angle R = ______

  4. Angles 112°112°, 68°68°, 95°95°. Fourth angle: ______

  5. One angle of a parallelogram is 90°90°. Other three: ______, ______, ______ Most specific name: ____________________


PAGE 11 — Angle practice

Angle Computation Frames

Independent practice.

  1. Missing angle measure.

    a) 100°+80°+100°+100° + 80° + 100° + ______ =360°= 360° → ______

    b) 55°+125°+55°+55° + 125° + 55° + ______ =360°= 360° → ______

    c) 90°+90°+130°+90° + 90° + 130° + ______ =360°= 360° → ______

  2. Parallelogram ABCDABCD, mA=47°m\angle A = 47°. mB=m\angle B = ______ mC=m\angle C = ______ mD=m\angle D = ______

  3. Parallelogram ABCDABCD, mA=(3x+5)°m\angle A = (3x + 5)° and mB=(2x)°m\angle B = (2x)°.

    Equation: ____________________________

    x=x = ______ mA=m\angle A = ______ mB=m\angle B = ______

  4. One angle of a rhombus is 108°108°. Others: ______, ______, ______

    Why does a rhombus follow parallelogram angle rules? ____________________________

  5. Isosceles trapezoid with a base angle of 74°74°. Other three: ______, ______, ______


PAGE 12 — Apply and reason

Angles in Context

  1. Application. A skateboard ramp side panel is a right trapezoid: two right angles, and the sloped front makes a 68°68° angle with the ground.

    Equation: ____________________________ Fourth angle: ______°

  2. Reasoning. Why does one angle determine all four angles of a parallelogram, but not of a general quadrilateral?




PAGE 13 — Exit ticket 14.3

Exit Ticket · Lesson 14.3

Name: ________________________ Date: ____________

  1. Angles 78°78°, 102°102°, 61°61°. Fourth: ______

  2. Parallelogram PQRSPQRS, mQ=115°m\angle Q = 115°. mP=m\angle P = ______ mR=m\angle R = ______ mS=m\angle S = ______

  3. Isosceles trapezoid with a base angle of 82°82°. The two angles at the other base: ______ and ______

  4. Explain with two triangles why the four angles of any quadrilateral add to 360°360°.




PAGE 14 — Sides you can copy

14.4 Finding Unknown Side Lengths

FIGURE: fig8-unknown-sides.png (full width)

Fill in the property.

In a parallelogram, ______________ sides are congruent.

In a rhombus or square, ______ sides are congruent.

In a rectangle, the diagonals are ______________.

In an isosceles trapezoid, the ______________ are congruent.

In any parallelogram, the diagonals ______________ each other.

Guided practice.

  1. Parallelogram ABCDABCD: 2x+3=2x + 3 = ______ x=x = ______ m=AD=m = AD = ______

  2. Rhombus EFGHEFGH: 3y1=3y - 1 = ______ y=y = ______ Each side: ______ Perimeter: ______

  3. Rectangle JKLMJKLM: p=KN=p = KN = ______ JL=JL = ______

  4. Parallelogram with sides 1313 and 88. Perimeter: ______

  5. Square with perimeter 5252. Side: ______


PAGE 15 — Side computation frames

Solve for the Unknown Length

Independent practice.

  1. Parallelogram ABCDABCD, AB=5xAB = 5x, DC=35DC = 35.

    Equation: ____________________ x=x = ______ AB=AB = ______

  2. Rhombus with sides 4t+34t + 3 and 2323.

    Equation: ____________________ t=t = ______ Perimeter: ______

  3. Parallelogram ABCDABCD, diagonals meet at MM: AM=9AM = 9, BM=6xBM = 6x, MD=18MD = 18.

    x=x = ______ AC=AC = ______ BD=BD = ______

  4. Rectangle ABCDABCD: AC=5nAC = 5n, BD=30BD = 30.

    n=n = ______ One half-diagonal: ______

  5. Isosceles trapezoid: legs 3w3w and 2121; bases 2626 and 1414.

    w=w = ______ Perimeter: ______


PAGE 16 — Apply and reason

Side Lengths in Context

  1. Application. A rectangular garden gate has a diagonal brace of 9191 in. A second brace runs along the other diagonal.

    Length needed: ______ in Property used: ____________________________

  2. Reasoning. Why does one side of a rhombus give you the perimeter, while one side of a parallelogram does not?




PAGE 17 — Exit ticket 14.4

Exit Ticket · Lesson 14.4

Name: ________________________ Date: ____________

  1. Parallelogram ABCDABCD, AB=3x+4AB = 3x + 4, DC=22DC = 22. x=x = ______

  2. Rhombus with side 99. Perimeter: ______

  3. Rectangle ABCDABCD, diagonals meet at NN, AN=11AN = 11. BD=BD = ______

  4. Only BC\overline{BC} is labeled in parallelogram ABCDABCD, with BC=14BC = 14. Why is AD=14AD = 14?



PAGE 18 — Review Part A

Chapter 14 Review · Properties (7.MG.3a)

  1. Always both pairs of opposite sides parallel: ____________________________

  2. Always four congruent sides: ____________________________

  3. Always four right angles: ____________________________

  4. Diagonals always bisect each other? Parallelogram ______ Rectangle ______ Rhombus ______ Square ______

  5. Always congruent diagonals: ____________________________

  6. Always perpendicular diagonals: ____________________________

  7. Lines of symmetry: square ______ · rectangle (not a square) ______ · rhombus (not a square) ______ · parallelogram (neither) ______ · isosceles trapezoid ______

  8. Two properties every rhombus has that a general parallelogram does not:

    ____________________________ and ____________________________


PAGE 19 — Review Part B

Chapter 14 Review · Sorting and Classifying (7.MG.3b)

  1. Four congruent sides and four right angles: ____________________

  2. Diagonals bisect and are congruent; sides 88, 55, 88, 55: ____________________

  3. Exactly one pair of parallel sides, congruent legs: ____________________

  4. Circle every name that applies to every square:

    quadrilateral · parallelogram · rectangle · rhombus · trapezoid

  5. Every parallelogram is a rectangle. T / F Reason: ____________________________

  6. Every square is a rhombus. T / F Reason: ____________________________

  7. Is a rectangle a trapezoid in this book? ______ Why? ____________________________

  8. Diagonals bisect and are perpendicular but not congruent: ____________________


PAGE 20 — Review Part C

Chapter 14 Review · Unknown Angles (7.MG.3c)

  1. Angles 96°96°, 84°84°, 113°113°. Fourth: ______

  2. Parallelogram ABCDABCD, mA=54°m\angle A = 54°. mB=m\angle B = ______ mC=m\angle C = ______ mD=m\angle D = ______

  3. Isosceles trapezoid, one base angle 71°71°. Other three: ______, ______, ______

  4. Consecutive angles (4x)°(4x)° and (5x)°(5x)°.

    Equation: ____________________ x=x = ______ Angles: ______ and ______

  5. One angle of a rhombus is 124°124°. Others: ______, ______, ______

  6. Right trapezoid with two right angles and a 55°55° angle. Fourth: ______


PAGE 21 — Review Part D

Chapter 14 Review · Unknown Sides (7.MG.3d)

  1. Parallelogram ABCDABCD, AB=4x5AB = 4x - 5, DC=27DC = 27. x=x = ______

  2. Rhombus with sides 6y6y and 3030. y=y = ______ Perimeter: ______

  3. Parallelogram diagonals meet at MM: AM=2zAM = 2z, MC=14MC = 14. z=z = ______ AC=AC = ______

  4. Rectangle ABCDABCD, AC=34AC = 34, diagonals meet at MM. BD=BD = ______ AM=AM = ______

  5. Isosceles trapezoid: legs 5k5k and 3535; bases 4040 and 2424. k=k = ______ Perimeter: ______


PAGE 22 — Review Part E

Chapter 14 Review · Application and Reasoning

  1. Application. A quilt block is a rhombus with side 77 in and one angle of 116°116°.

    Perimeter: ______ in All four angles: ______, ______, ______, ______

  2. Application. A rectangular window frame has one diagonal measuring 8080 in.

    The other diagonal should measure: ______ in

    What would a measurement of 7878 in mean? _______________________________________________

  3. Reasoning. Why is every square a rectangle, but not every rectangle a square?


  4. Reasoning. A student says any quadrilateral with two pairs of congruent sides must be a parallelogram.

    Counterexample: ____________________________

    What was overlooked? _______________________________________________

  5. Reasoning. You can see only the two diagonals of a quadrilateral and how they cross. How do you tell a rectangle, a rhombus, and a square apart?

    Rectangle: ____________________________

    Rhombus: ____________________________

    Square: ____________________________


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