## S. K. Gupta Anubhuti Gangal Class 5 Math Fifteenth Chapter Perimeter And Area Exercise 52

## EXERCISE 52

**AREA:** *Area of a shape is the amount of space it covers.*

**(1) Copy and complete the table for the area rectangles:**

(a) Length = 20 cm, Width = 8 cm

Solution: Area = (20 × 8) cm^{2} = 160 cm^{2}

(b) Length = 14 km, Width = 10 km

Solution: Area = (14 × 10) km^{2} = 140 km^{2}

(c) Length = 13 mm, Width = 3 mm

Solution: Area = (13 × 3) mm^{2} = 39 mm^{2}

(d) Length = 12.5 m, Width = 10 m

Solution: Area = (12.5 × 10) m^{2} = 125 m^{2}

(e) Length = 25 mm, Width = 60 mm

Solution: Area = (25 × 60) mm^{2} = 1500 mm^{2}

**(2) Calculate the area of each of the objects shown below:**

Solution: (a) The required area = (6 × 9) cm^{2} = 54 cm^{2}

(b) The required area = (11 × 10.5) cm^{2} = 115.5 cm^{2}

(c) The required area = (1.2 × 1.5) m^{2} = 1.8 m^{2}

(d) The required area = (13.41 × 6.10) m^{2} = 81.801 m^{2}

**(3) Find the area of each of the rectangles described below:**

(a) 4 cm by 3 cm

Solution: Area = (4 × 3) cm^{2} = 12 cm^{2}

(b) 8 cm by 6 cm

Solution: Area = (8 × 6) cm^{2} = 48 cm^{2}

(c) 20 cm 15 cm

Solution: Area = (20 × 15) cm^{2} = 300 cm^{2}

(d) 28 cm by 21 cm

Solution: Area = (28 × 21) cm^{2} = 588 cm^{2}

(e) Length = 1 m 75 cm, Width = 80 cm

Solution: Here, 1 m 75 cm = 175 cm

Area = (175 × 80) cm^{2} = 14000 cm^{2}

**(4) Find the area of a square whose one side is**

(a) 3 cm

Ans: Area = (3)^{2} cm^{2} = 9 cm^{2}

(b) 5 cm

Ans: Area = (5)^{2} cm^{2} = 25 cm^{2}

(c) 13 cm

Ans: Area = (13)^{2} cm^{2} = 169 cm^{2}

(d) 1.2 cm

Ans: Area = (1.2)^{2} cm^{2} = 1.44 cm^{2}

(e) 2.5 cm

Ans: Area = (2.5)^{2} cm^{2} = 6.25 cm^{2}

(f) 30 m

Ans: Area = (30)^{2} cm^{2} = 900 cm^{2}

(g) 13.4 km

Ans: Area = (13.4)^{2} cm^{2} = 179.56 cm^{2}

(h) 100 m

Ans: Area = (100)^{2} cm^{2} = 10000 cm^{2}

(i) 12.16 m

Ans: Area = (12.16)^{2} cm^{2} = 147.8656 cm^{2}

**(5) Which square unit would you use to measure the area of:**

(a) A page of this book

Ans: sq cm

(b) A stamp

Ans: sq mm

(c) The classroom floor

Ans: sq m

(d) Delhi

Ans: sq km

(e) The blackboard

Ans: sq m

(f) An insect’s wing

Ans: sq mm

(g) The Indian Ocean

Ans: sq km

(h) A sports field

Ans: sq m

**(6) Choose the best estimate for the area. Write a, b or c.**

(i) An envelope

Ans: (a) 200 cm^{2}

(b) 200 mm^{2}

(ii) A page of newspaper

Ans: (b) 2640 cm^{2}

**(7) Mary is making a quilt from square pieces of cloth. She fits 10 pieces along one side and 15 pieces along the other. How many pieces does she need?**

Solution: The area of the cloth = (10 × 15) pieces = 150 pieces

Therefore, Mary needs a quilt from square of 150 pieces cloth.

**(8) What is the area of the front of a watch that is 25 mm wide and 23 mm high?**

Solution: The required area = (25 × 23) mm^{2} = 575 mm^{2}

**(9) Compare the areas of square 15 cm on each side and a rectangle 11 cm by 8 cm. Which figure has the greater area and by how much?**

Solution: Area of the square = (15)^{2} cm^{2} = 225 cm^{2}

Area of the rectangle = (11 × 8) cm^{2} = 88 cm^{2}

**(10) A rectangular field measures 400 m by 100 m and a square field 200 m by 200 m.**

(i) Do the two fields have the same area?

Ans: Yes, the both fields have the same area.

(ii) Which field requires more fencing and by how much more?

Ans: Rectangular field, 200 meters more.