Practice the questions of **McGraw Hill Math Grade 4 Answer Key PDF Chapter 10 Lesson 9 Problem Solving: Using Formulas **to secure good marks & knowledge in the exams.

## McGraw-Hill Math Grade 4 Answer Key Chapter 10 Lesson 9 Problem Solving: Using Formulas

**Solve**

Question 1.

Mr. Smith wants to build a fence around his backyard. It is square-shaped and measures 7 meters on one side. How many meters of fence will Mr. Smith need to build?

Answer:

(2 Ã— 7) + (2 Ã— 7) = 28m

Explanation:

Mr. Smith wants to build a fence around his backyard

It is square-shaped and measures 7 meters on one side

Perimeter of a square = (2 x l) + (2 x w)

That is (2 Ã— 7) + (2 Ã— 7)

= 14 + 14

= 28

So, Mr. Smith need 28 m to build the fence.

Question 2.

Gary builds a rectangular rabbit pen. The pen measures 6 feet by 8 feet. How many square feet is the pen?

Answer:

48 square feet

Explanation:

Gary builds a rectangular rabbit pen

The pen measures 6 feet by 8 feet

Area of a rectangle = l x w

Length of the pen is 6 feet

Width of the pen is 8 feet

Area – l x w = 6 x 8 = 48 feet

So, the area of the rectangular pen is 48 square feet.

Question 3.

The town of Grand Sun marks off a large rectangular patch of land as a forest preserve. The land measures 14 kilometers long and 8 kilometers wide. What is the total area of the forest preserve?

Answer:

112 square kilometers

Explanation:

The town of Grand Sun marks off a large rectangular patch of land as a forest preserve

The land measures 14 kilometers long and 8 kilometers wide

Area of a rectangle = l x w

Length of the rectangular patch of land is 6 km

Width of the rectangular patch of the land is 8 km

Area – l x w = 14 x 8 = 112

So, the area of the rectangular patch of land is 112 square kilometers.