Page 171 - Math Skill - 5

Perimeter, Area and Volume 169

Breadth of the floor = 3 m = 3 × 100 cm = 300 cm

Area of the floor = 800 cm × 300 cm = 240000 cm 2
Fact-o-meter
Length of a tile = 20 cm
Square centimetre or
Breadth of a tile = 15 cm square metre can be
2
2
Area of the tile = 20 cm × 15 cm written as cm or m .
= 300 cm 2

To obtain the number of tiles, divide the floor area by the area of a single tile.

Area of the floor 240000 cm 2
Number of tiles required = = = 800
Area of the tile 300 cm 2

Required number of tiles to cover the floor are = 800 tiles

Example 4: Area of a rectangle is 315 sq cm. If the length of the rectangle is 15 cm, find
its breadth.
Solution: Length of a rectangle = 15 cm, Area = 315 sq cm

Area 315
Breadth of a rectangle = = cm = 21 cm
Length 15

The breadth of the rectangle is 21 cm.

Exercise 13.2

1. Find the area of the rectangle whose sides are:
(a) Length = 112 m, Breadth = 60 m (b) Length = 70.5 cm, Breadth = 16 cm

(c) Length = 12.5 cm, Breadth = 8 cm (d) Length = 130 m, Breadth = 75 m

2. Find the length of the rectangle whose:

(a) Area = 400 sq cm, Breadth = 16 cm (b) Area = 800 sq cm, Breadth = 25 cm
(c) Area = 110 sq cm, Breadth = 11 cm (d) Area = 696 sq m, Breadth = 12 m

3. Find the area of square whose side is:

(a) 15 cm (b) 55 cm (c) 20 cm (d) 18 cm (e) 54 cm
4. Shreya made a rectangular wall painting of dimensions 2.5 m and 1.5 m. Find the area of
the painting in sq. m and sq. cm both.

5. Sumit ploughed a rectangular field of length 320 m and breadth 210 m. Find the total area
ploughed by him.

6. The side of a square hall measures 80 m each. Find the area. If it costs ` 0.50 per sq. m to
tile the floor, how much will it cost to tile the entire floor?