# Math in Focus Grade 4 Chapter 12 Practice 1 Answer Key Area of a Rectangle

This handy Math in Focus Grade 4 Workbook Answer Key Chapter 12 Practice 1 Area of a Rectangle detailed solutions for the textbook questions.

## Math in Focus Grade 4 Chapter 12 Practice 1 Answer Key Area of a Rectangle

Find the area of each figure.

Example

There are 3 rows of one-inch squares.
Each row has 4 one-inch squares.
3 × 4 = 12
There are 12 one-inch squares covering rectangle A.
Area of rectangle A = 12 in.2

Question 1.

There ore ___________ rows of one-meter squares.
Each row has __________ one-meter squares.
________ × ________ = ________
There are __________ one-meter squares covering rectangle B.
Area of rectangle B = ___________ m2
There are 7 rows of one-meter squares.
Each row has 3 one-meter squares.
7 × 3 = 21
There are 21 one-meter squares covering rectangle B.
Area of rectangle B = 21 m2

Look at the rectangles in the grid. Write the length, width, and area of each rectangle in the grid. Give your answers in the correct units.

Question 2.

Complete to find the area of each figure.

Question 3.

Area = length × width
= __________ × __________
= ___________ yd2
The area is ___________ square yards.
Length = 5 yards
width = 2 yards
Area = length × width
=5yd × 2yd
= 10 yd2
The area is 10 square yards.

Question 4.

Area = __________ × __________
= ___________ ft2
The area is ___________ square feet.
In the above image we can observe length and width.
Length = 16 feet
width = 4 feet
Area = 16 feet × 4 feet
= 64 ft2
The area is 64 square feet.

Find the perimeter and area of each rectangle or square.

Example

Perimeter = 18 ft
Area = 14 ft2

Question 5.

Perimeter = ___________ in.
Area = __________ in2
In the above image we can observe a square.
Side = 4 inch
Perimeter of square = 4 × S
= 4 × 4 inch
= 16 inch
Perimeter of square = 16 inch
Area of a square = side2
= 4 × 4
= 16 in2
Area of square = 16 in2
Question 6.

Perimeter = ___________ ft.
Area = __________ ft2
In the above image we can observe a rectangle.
length = 6 feet
width = 2 feet
Perimeter of rectangle = 2 (l + w)
= 2 (6 feet + 2 feet)
= 2 (8 feet)
= 16 feet
Perimeter of rectangle = 16 feet.
Area of rectangle = length x width
= 6 feet × 2 feet
= 12 ft2
Area of rectangle = 12 ft2
Question 7.

Perimeter = ___________ yd.
Area = __________ yd2
In the above image we can observe a rectangle.
length = 5 yards
width = 4 yards
Perimeter of rectangle = 2 (l + w)
= 2 (5 yards + 4 yards)
= 2 (9 yards)
= 18 yards
Perimeter of rectangle = 18 yards.
Area of rectangle = length x width
= 5 yards × 4 yards
= 20 yd2
Area of rectangle = 20 yd2

Example

Ashley has a rug that measures 3 yards by 2 yards on her bedroom floor.
What area of her bedroom floor is covered by the rug?

Area = length × width
= 3 × 2
s = 6 yd2
The area of her bedroom floor covered by the rug is 6 square yards.

Question 8.
Paula wants to paint one of the walls in her room blue. The wall measures 5 meters by 3 meters. What is the area of the wall she has to paint?

In the above image we can observe length and width.
Length = 5 m
width = 3 m
Area of the wall = length ×  width
= 5 m x 3 m
= 15 m2
The area of the wall she has to paint is 15 square meters.
Question 9.
The area of a nature reserve is 100 square miles. Oak trees were planted on a square plot of land in the nature reserve with sides that measure 8 miles each. What area of the nature reserve is not covered by oak trees?
The area of a nature reserve = 100 square miles.
The area of oak trees = 8 mi x 8 mi = 64 mi2
The area not covered by oak trees = area of a nature reserve – area of oak trees
= 100 – 64
= 36 mi2
Area of the nature reserve is not covered by oak trees are 36 square miles.

Question 10.
Yolanda has a piece of rectangular fabric measuring 30 centimeters by 9 centimeters. She uses half of the material to make a puppet. What is the area of the leftover fabric?
Area of the rectangular fabric = length ×  width
= 30 cm ×  9 cm
= 270 cm2
She used half of the material to make a puppet.
= 270/2
= 135 cm2
The area of the leftover fabric is 135 square centimeters.

Estimate the area of each figure in square units.

Example

Estimated area = 14 – 15 square units

Question 11.

Estimated area = __________ square units.