Question

The perimeter of rectangle is 400 m . if the sides are in ratio 7:3 . find the area
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Answer 1

Answer:

let 7x and 3x be the sides of the rectangle

perimeter=400m

2(l+b) = 400m

2(7x+3x)=400

2 x 10x= 400

20x =400

x= 400/20

x= 20

then sides are 7x = 7 x 20 = 140m

3x = 3 x20 = 60 m

Answer 2

Answer:

let the sides be 7x and 3x

Then,

Perimeter of rectangle = 400

2(l+b). = 400

2(7x+3x) =. 400

20x. = 400

x. = 400/20

x. =. 20

Therefore, l =20×7 = 140

b = 20×3 = 60

Therefore, Area = 140×60 = 840