Question

the len ght and breath of a rectangle are in ratio 5:3.if the rectangle is 1215 m square,ffind its perimeter .

Answer 1

Let the length be 5x and breadth be 3x.

$area \: of \: rectangle = l \times b$

1215=5x × 3x

1215=15x²

x²=81

x=9

LENGTH: 5x= 45m

BREADTH: 3x=27m

$perimeter \: of \: rectangle = 2(l + b)$

perimeter=2(45+27)

=2× 72

= 144m

Answer 2

Let length and breath be 5x&3x

Area=1215m square

That implies 5x.3x=1215

15xsquare=1215

X square= 81

X=9

Lenght=45

Breath= 27

Perimeter= 2.45+27

72.2=144