We included **HMH Into Math Grade 5 Answer Key PDF** **Module 20 Lesson 1 Identify and Classify Polygons **to make students experts in learning maths.

## HMH Into Math Grade 5 Module 20 Lesson 1 Answer Key Identify and Classify Polygons

I Can identify and classify polygons.

**Spark Your Learning**

Many of the figures found in art, nature, and science are familiar.

Group the polygons shown based on two or more features, or attributes, they have in common.

Answer:

Triangles,

and polygons

Explanation:

There are 4 triangles

a triangle has 3 sides and 3 corners.

Trapezoid, square, rectangle have 4 sides and 4 corners.

and a hexagon it has 6 sides and six angles.

**Turn and Talk** Into which of your groups would you place this polygon? Explain your reasoning.

Answer:

Octagon.

Explanation:

An octagon is a 2D shape that has 8 sides, 8 angles and 8 vertices.

Octagons can be regular or irregular

**Build Understanding**

Question 1.

Mr. Berger and his class are looking at the polygon shown.

A. Record the attributes of different polygons in the table.

- Complete the column for the figure that has 7 vertices.
- Complete the column for nonagon.
- Draw two other polygons and complete the columns.

Answer:

Connect to Vocabulary

The prefix hepta- is Greek for the number 7, so a heptagon is a polygon with seven sides. The prefix nona- is Latin for the number 9, so a nonagon is a polygon with nine sides.

B. What do you notice about the attributes of each polygon?

Answer:

Heptagon:

Heptagon is a polygon a closed shape made up of line segments made up of 7 sides and 7 angles.

Nonagon:

A nine-sided shape is a polygon called a nonagon.

It has nine straight sides that meet at nine corners, or vertices

**Turn and Talk** If you add one side to a polygon, how do the numbers of sides and vertices change? What if you add two sides?

Answer:

A regular polygon has 5 sides

if we add 1 side then it has 6 sides

so, when it has 6 sides it is called hexagons for a hexagon it has 6 sides and 6 vertices

if we add 2 side then it has 8 sides

so, when it has 8 sides it is called octagon for a octagon it has 8 sides and 8 vertices

Question 2.

Mr. Berger drew these polygons on a whiteboard.

Connect to Vocabulary

The word congruent describes equal angle measures or equal side lengths in a figure.

A regular polygon is a polygon in which all sides are congruent and all angles are congruent.

A. What do you notice about the attributes of the polygons in Group 1?

Answer:

It has equal sides and and angles

so, they are congruent.

A regular polygon is a polygon in which all sides are congruent and all angles are congruent.

B. What do you notice about the attributes of the polygons in Group 2?

Answer:

In group 2 there sides are in different sizes

and angles and sides are not congruent.

C. Describe both groups of polygons using the words congruent and regular.

Answer:

In group 1 they are regular and congruent

in group 2 they are irregular and not congruent.

**Turn and Talk** Draw a regular polygon and a polygon that is not regular on a separate sheet of paper. Compare and contrast your drawings with those of a classmate.

Answer:

Friend 1:

Friend 2:

Explanation:

These 2 charts are the comparisons between 2 friends

about regular and irregular polygons.

**Check Understanding**

Question 1.

Tam is cutting pieces of stained glass for a design. How would she determine whether the figures she cuts are regular polygons or not?

Answer:

Tam is cutting pieces of stained glass for a design.

If we cut them in a irregular manner we cannot frame them

so, we have to cut them in a regular frame or a regular design.

**On Your Own**

Question 2.

**Use Structure** Honeycombs use the repeated shape of one type of polygon. Identify this polygon and the numbers of its sides, angles, and vertices. How does knowing any one of these help you know the other three?

Answer:

Hexagons

Explanation:

Honeycombs are the frame of regular Hexagons

A regular hexagon is a 2 dimensional shape

with 6 sides, 6 vertices and 6 angles.

**Use Structure** Name the polygon. Tell whether it is a regular polygon or not a regular polygon and its number of sides.

Question 3.

Answer:

Nonagon

Explanation:

A regular Nonagon has 9 sides and 9 angles and 9 vertices

And it is a regular nonagon.

Question 4.

Answer:

Right angled triangle

Explanation:

A triangle in which one of the interior angles is 90° is called a right triangle.

the angle bounded by two lines perpendicular to each other with an angle of 90°

Question 5.

**Use Tools** Kim connects 7 of the dots on the dot paper.

She says the figure has seven sides, so she has drawn a heptagon. Is she correct? Explain.

Answer:

No.

A heptagon is a closed figure with 7 sides and 7 vertices and 7 angles

so, it is not a heptagon.

The above figure has 6 sides and 6 vertices

Connect the dots at the top. Name the polygon and tell how many sides and angles it has.

Answer:

Explanation:

It is a irregular heptagon

An irregular heptagon is any heptagon with sides and angles that are not all congruent.

It has 7 sides, 7 angles and 7 vertices.

**I’m in a Learning Mindset!**

What would I like to learn more about when I am studying the classification of polygons?

Answer:

We have learned that a polygon is a flat shape with straight sides.

A regular polygon is a polygon in which all sides are congruent and all angles are congruent.

A regular polygon has all its sides and angles equal.

An irregular polygon does not have all sides and angles equal.