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 = ___________ m^{2}

Answer:

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** m^{2}

**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.

Answer:

**Complete to find the area of each figure.**

Question 3.

Area = length × width

= __________ × __________

= ___________ yd^{2}

The area is ___________ square yards.

Answer:

**Length = 5 yards**

**width = 2 yards**

Area = length × width

=5yd × 2yd

= **10 yd ^{2}**

The area is

**10**square yards.

Question 4.

Area = __________ × __________

= ___________ ft^{2}

The area is ___________ square feet.

Answer:

In the above image we can observe length and width.

**Length = 16 feet**

**width = 4 feet**

Area = 16 feet × 4 feet

= **64** ft^{2}

The area is **64** square feet.

**Find the perimeter and area of each rectangle or square.**

**Example**

Perimeter = 18 ft

Area = 14 ft^{2}

Question 5.

Perimeter = ___________ in.

Area = __________ in^{2}

Answer:

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 = side^{2
}= 4 × 4

= 16 in^{2}

**Area of square = 16 in ^{2}**

Question 6.

Perimeter = ___________ ft.

Area = __________ ft

^{2}

Answer:

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 ft

^{2 }

**Area of rectangle = 12 ft**

^{2}Question 7.

Perimeter = ___________ yd.

Area = __________ yd

^{2}

Answer:

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 yd

^{2}

^{ }

**Area of rectangle = 20 yd**

^{2}**Solve. Show your work.**

**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 yd^{2}

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?

Answer:

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 m^{2
}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?

Answer:

The area of a nature reserve = 100 square miles.

The area of oak trees = 8 mi x 8 mi = 64 mi^{2}

The area not covered by oak trees = area of a nature reserve – area of oak trees

= 100 – 64

= 36 mi^{2}

Area of the nature reserve is not covered by oak trees are 36 square miles.

**Solve. Show your work.**

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?

Answer:

Area of the rectangular fabric = length × width

= 30 cm × 9 cm

= 270 cm^{2}

She used half of the material to make a puppet.

= 270/2

= 135 cm^{2}

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.

Answer:

Estimated area = **13 – 14** square units.

Question 12.

Estimated area = __________ square units.

Answer:

Estimated area = 6 – 7 square units.