Lesson
8-6B
Classifying Quadrilaterals
Common
Core
How are special quadrilaterals
related to each other?
5.G.4 Classify twodimensional figures in
a hierarchy based on
properties.
This “family tree” shows how
special quadrilaterals are
related to each other.
Quadrilaterals
Parallelogram
Rectangle
Trapezoid
Rhombus
Square
Guided Practice
MATHEMATICAL
PRACTICES
Do you know HOW?
Do you UNDERSTAND?
Tell whether each statement is true
or false.
4. Look for Patterns Explain how the
family tree diagram shows that every
square is a rectangle.
1. All rectangles are squares.
2. Every rhombus is a parallelogram.
5. How are a rectangle and a rhombus
alike?
3. Parallelograms are special rectangles.
Independent Practice
MATHEMATICAL
PRACTICES
6. The figure shown below is an isosceles
trapezoid. The two sides that are not
parallel have the same length. How
could you add this shape to the family
tree diagram?
7. What properties does the shape below
have? Why is it not a parallelogram?
8. Why is a square also a rhombus?
9. Look for Patterns Why is a
parallelogram not the same type of
quadrilateral as a trapezoid? Explain
how you know.
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All of the figures below the parallelogram
have two pairs of parallel opposite sides.
Each branch of the tree shows a
subgroup of the figure above.
A square is a type of rectangle.
Parallelogram
All rectangles are parallelograms.
Each figure shares all of the
properties of the figures above it.
Rectangle
A square and a rectangle have four right
angles.
Rhombus
Square
MATHEMATICAL
Problem Solving
PRACTICES
10. Construct Arguments Draw a
quadrilateral with one pair of parallel
sides and two right angles. Explain
why this figure is a trapezoid.
11. Use Tools A rhombus has a side
length of 6 m. What is the perimeter?
Explain how you found your answer.
12. Classify this polygon using as many
names as possible.
13. Critique Reasoning Ann says the
figure below is a square. Pablo says
that it is a parallelogram. Felix says that
it is a rectangle. Can they all be right?
Explain.
14. Reasonableness Which shows
the most likely side lengths for a
rectangle?
15. All parallelograms have opposite
sides parallel. Are squares and other
rectangles parallelograms?
A 4, 4, 4, 3
B 3, 4, 3, 4
C 3, 3, 3, 6
D 3, 3, 3, 4
16. Draw a quadrilateral that is not a
trapezoid and not a parallelogram.
Lesson 8-6B
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