Question

ln a design made from tiles each of dimensions 40 cm by 60 cm, find
the ratio of
(a) the perimeter of shaded portion to the perimeter of the whole design
(b)the area of the shaded portion to the area of the unshaded portion
​

Answer 1

Answer:

From the above figure, we find that:

Perimeter of shaded portion = 10 units

Perimeter of whole design = 18 units

Area of shaded portion = 6 sq. units

Area of whole design = 20 sq. units

hu

Also, area of unshaded portion = Total area - Area of the shaded portion

= 20 - 6 = 14 sq. units

a) Ratio of perimeter of the shaded portion to the perimeter of the whole design

Perimeter of shaded portion/Perimeter of whole design

10 /18

5/9

5:9

[on dividing numerator and denominator by 2]

b) Ratio of area shaded portion to the area of unshaded portion

=

Area of shaded portion/Area of unshaded portion

6/20-6

6/14

3/7

3:7

[on dividing numerator and denominator by 2]