We included **HMH Into Math Grade 5 Answer Key PDF** **Module 20 Review **to make students experts in learning maths.

## HMH Into Math Grade 5 Module 20 Review Answer Key

**Vocabulary**

Question 1.

Write each term in the correct section of the Venn diagram.

- equilateral triangle
- isosceles triangle
- regular heptagon
- regular nonagon
- scalene triangle

Answer:

Explanation:

A polygon is called regular if it has equal sides and angles.

Nonagon has 9 sides 9 angles and 9 vertices

Heptagon has 7 sides 7 angles and 7 vertices.

If all the three sides are different in length, then its scalene triangle.

If any two sides are equal in length, then it is an isosceles triangle.

If all three sides are equal in length, then it is an equilateral triangle.

**Concepts and Skills**

Question 2.

**Use Tools** Which statement is true? Tell what strategy or tool you will use to answer the question, explain your choice, and then find the answer.

(A) All right triangles are also acute triangles,

(B) All obtuse triangles are also scalene triangles.

(C) All isosceles triangles are also equilateral triangles.

(D) All equilateral triangles are also isosceles triangles.

Answer: D

Explanation:

All equilateral triangles are also isosceles triangles.

Isosceles = at least TWO sides of equal length.

Equilateral = ALL THREE sides of equal length. Therefore, at least two of them

By definition all sides of an equilateral triangle are equal in length and all angles are equal in degree measure.

**Write always, sometimes, or never to make the statement true for 3-5.**

Question 3.

A regular quadrilateral is ___________ a square.

Answer:

sometimes

Explanation:

Square is a quadrilateral with four equal sides and angles.

It’s also a regular quadrilateral as both its sides and angles are equal.

Question 4.

A rhombus is ___________ a parallelogram.

Answer:

always

Explanation:

All rhombuses are parallelograms,

but not all parallelograms are rhombuses.

Question 5.

A parallelogram is ___________ a rectangle.

Answer:

sometimes

Explanation:

A parallelogram is a rectangle.

This is sometimes true.

It is true when the parallelogram has 4 right angles

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

Question 6.

Answer:

Hexagon.

Explanation:

a hexagon can be defined as a polygon with six sides.

The two-dimensional shape has 6 sides, 6 vertices and 6 angles.

Question 7.

Answer:

Irregular polygon.

Explanation:

9 sides

9 vertices.

6 angles

Irregular polygons are the kinds of closed shapes that do not have the side length equal to each other

and the angles equal in measure to each other

Write the number of the section of the Venn diagram where each figure should be placed when a trapezoid is defined as having at least one pair of parallel sides.

Question 8.

Answer:

Trapezoid.

Explanation:

A trapezoid is a quadrilateral with one pair of opposite sides parallel.

It belongs to the number 5 in the Venn Diagram.

It is a quadrilateral.

Question 9.

Answer:

Rhombus

Explanation:

Rhombus is a quadrilateral whose four sides all have the same length.

So opposite sides are congruent and quadrilateral MNOP is a parallelogram.

Also, adjacent sides are congruent, so parallelogram MNOP is a rhombus.

Question 10.

Select all the categories that always describe a figure in which all of the angles have the same measure.

(A) decagon

(B) regular decagon

(C) regular polygon

(D) polygon

(E) hexagon

(F) square

Answer:

(B) regular decagon

(C) regular polygon

Explanation:

When we say regular then it has equal sides and equal lengths and angles with same measure.

and they are congruent to.

In general a polygon is considered weather it is regular or irregular.

Question 11.

List as many attributes as possible for a figure that can be placed in the overlapping area of the Venn diagram. Name the figure.

Answer:

Explanation:

A rhombus has all sides equal,

while a rectangle has all angles equal.