# Into Math Grade 4 Module 9 Lesson 1 Answer Key Apply the Area Formula to Rectangles

We included HMH Into Math Grade 4 Answer Key PDF Module 9 Lesson 1 Apply the Area Formula to Rectangles to make students experts in learning maths.

## HMH Into Math Grade 4 Module 9 Lesson 1 Answer Key Apply the Area Formula to Rectangles

I Can find the area of a rectangle by using the formula for area.

Making banners is a very old craft. Banners are usually made of cloth and can have a symbol, logo, slogan, or any other message. How can you find the area of each banner? The area can be calculated by using the formula,

Area = Length x width.

for the first banner

Area = 5 x 8 = 40 square feet

for the second banner,

Area = 4 x 10 = 40 square feet. Turn and Talk What do you notice about the perimeter and area of each banner?

Perimeter gives the total circumference of the rectangle whereas, Area gives the total number of units that fit in the given figure or banner.

Build Understanding

1. Sports fans use banners to show support. How can you find the area of the banner? A. What does it mean to find the area of a flat surface?
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Area is a measure of how much space there is on a flat surface.
To find the area, think about the measure of the sides of the rectangle.
B. How many unit squares make up the length and width of the rectangle?
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28 unit squares make up the length and width of the rectangle

C. Count the number of unit squares to find the area. __________________________________

28 unit squares required to find the area.
D. What is the relationship between the length and width and the area? __________________________________

the relationship between the length and width and the areais

Area = Length X Width.

E. How can you describe a mathematical rule or formula that you would use to find the area (A) of the rectangle? Write the formula. Represent the length with l and the width with w.
_________________________________ Area = Length X Width.

Connect to Vocabulary
You can also write the formula for the area (A) of a rectangle as A = b × h. Think of the base (b) of a rectangle as the measure of any side. The height (h) of the rectangle is the measure of a side perpendicular to the base.

F. How can you use the area formula to find the area of the rectangle?

A = l × w
A = __ × ___
A = ___

A = l × w

A = 7 x 4

A = 28 square units.

G. The rectangle has an area of ___ square units.

The rectangle has an area of 28 square units

Step It Out

2. The Hawks’ fans are making a giant banner for a competition. The banner has the dimensions shown. What is the area of the banner?
A. Write the formula that you can use to solve the problem.

Area = Length x Width
B. Write the measure of the length, l, and the width, w, of the banner.

From the figure,

Length = 5 meters

Width = 7 meters.

C. Find the area of the banner.

From formula,

Area = Length x width

Area = 5 x 7 = 35 square meters.

D. The area of the banner The area is ___ square meters.

The area of the banner The area is 35 square meters. Area = Length x width

Area = 5 x 7

Area = 35 square meters.

Turn and Talk How would the area of the banner change if the banner was turned so that the width is 7 meters and the length is 5 meters?

there will be no change in the area of the rectangle. Because, 5 x 7 = 7 x 5 = 35 square meters only.

Check Understanding Math Board

Question 1.
Mr. Nielsen is going to buy sod for a portion of his yard, but first, he must know the area of the surface that he wants to cover. What is the area? ___________________

From the figure,

Area = Length x width

Area = 18 x 25

Area = 450 square feet.

Therefore, Area of the figure is 450 square feet.

Find the area.

Question 2. From the figure,

Area = Length x width

Area = 9 x 6

Area = 54 square m.

Therefore, Area of the figure is 54 square m.

Question 3. From the figure,

Area = Length x width

Area = 10 x 10

Area = 100 square ft.

Therefore, Area of the figure is 100  square ft.

Question 4.
Jason has a sticker on a folder. What is the area of the sticker? From the figure,

Area = Length x width

Area = 7 x 3

Area = 21 square cm.

Therefore, Area of the sticker on folder is 21 square cm.

Question 5.
Lisa is setting square tiles on a backsplash. What is the area of each tile? From the figure,

Area = Length x width

Area = 5 x 5

Area = 25 square in

Therefore, Area of the each tile is 25  square in.

Question 6.
Reason Mr. Wells knows that the area of the square floor in a toolshed is 36 square feet. What is the length of one of the sides? How do you know?

We know,

Area of square = side x side

36 = side x side

side = square root of 36 = 6

Therefore, length of one of the sides = 6 ft.

Use Structure Find its area.

Question 7. From the figure,

Area = Length x width

Area = 14 x 6

Area =84 square  cm

Therefore, Area of the figure is 84 square cm.

Question 8. From the figure,

Area = Length x width

Area = 3 x 11

Area = 33 square in.

Therefore, Area of the figure is 33 square in.

Question 9. From the figure,

Area = Length x width

Area = 8 x 8

Area = 64 square cm.

Therefore, Area of the figure is 64 square cm.

I’m in a Learning Mindset!

What parts of solving problems using the area formula am I comfortable with?
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