Practice the questions of **McGraw Hill Math Grade 8 Answer Key PDF Lesson 16.4 Calculating Perimeter and Area with Metric Units **to secure good marks & knowledge in the exams.

## McGraw-Hill Math Grade 8 Answer Key Lesson 16.4 Calculating Perimeter and Area with Metric Units

**Exercises**

**CALCULATE**

Question 1.

What is the perimeter of a square with sides of 10 cm?

What is the area?

Answer:

Perimeter =40 cm; Area = 100 sq cm,

Explanation:

the perimeter of of a square = 4 x side = 4 x 10 cm = 40 cm,

The area of a square = side x side = 10 cm X 10 cm = 100 sq cm.

Question 2.

What is the perimeter of the figure?

Answer:

38 cm,

Explanation:

The perimeter of a a given figure,

P = 6 cm + 4 cm + 3 cm + 2 cm + 9 cm + 14 cm = 38 cm.

Question 3.

A rectangle has sides of 4.4 cm and 6 cm. What is the perimeter of the rectangle? What is the area?

Answer:

Perimeter of a rectangle = 20.8 cm,

Area of a rectangle = 26.4 sq cm,

Explanation:

Perimeter of a rectangle = 2[length + breadth],

= 2[6 cm + 4.4 cm] = 20.8 cm,

Area of a rectangle = length x breadth = 6 cm X 4.4 cm,

= 26.4 sq cm.

Question 4.

What is the perimeter of a rectangle with 2 sides of 12 meters and 2 sides of 6 meters? What is the area?

Answer:

Perimeter of a rectangle = 36 m,

Area of a rectangle = 72 sq m,

Explanation:

Perimeter of a rectangle = 2[length + breadth],

= 2[12 m + 6 m] = 36 m,

Area of a rectangle = length x breadth = 12 m X 6 m = 72 sq m.

Question 5.

What is the area of the triangle?

Answer:

90 sq m,

Explanation:

The are of a triangle = 1/2[base X height] =1/2 [15 m x 12 m],

= 1/2 x 180 sq m = 90 sq m.

Question 6.

What is the area of the triangle?

Answer:

24 sq m,

Explanation:

The area of a triangle = 1/2[base X height] =1/2 [12 m X 4 m],

= 1/2 X 48 sq m = 24 sq m.

Question 7.

Ariel is cleaning a rug that is 4.2 meters long and 3 meters wide. If the dry cleaning store charges $18.00 per square meter to clean it, how much will she pay to clean the rug? What is the perimeter of the rug?

Answer:

She will pay $226.80,

Perimeter of rug is14.4 m,

Explanation:

Length L = 4.2 m, Width W = 3 m, Area of rug = L X W,

A = 4.2 m X 3 m, A = 12.6 sq m,

the dry cleaning store charges $18.00 per square meter,

she pay to clean the rug is 12.6 x $18 = $ 226.80,

The perimeter of the rug is perimeter of a rectangle =

2[Length + Breadth] = 2[4.2 m + 3 m] = 2 X 7.2 m = 14.4 m.