Question

A pair of adjacent sides of a rectangle are in the ratio 4:3.if its diagonal is 20cm. find the lenght of its sides and hence the area of the rectangle

Answer 1

Hi ,

Let l and b are two adjacent sides of a

rectangle ,

l : b = 4 : 3

Let l = 4x ,

b = 3x

diagonal ( d ) = 20 cm

l² + b² = d²

( 4x )² + ( 3x )² = ( 20 )²

16x² + 9x² = 400

25x² = 400

x² = 400/25

x² = 16

x = 4

Therefore ,

l = 4x = 4 × 4 = 16 cm

b = 3x = 3 × 4 = 12 cm

area of the rectangle = lb

A = 16 × 12

A = 192 cm²

I hope this helps you.

:)