Question

the area of rectangle is 102 sqcm .if it's length is 17 cm, what is its perimeter?

Answer 1

73

Q:

If the diagonal of a rectangle is 17cm long and its perimeter is 46 cm. Find the area of the rectangle.

A) 110B) 120C) 130D) 140

Answer:   B) 120 

Explanation:

let length = x and breadth = y then  

2(x+y) = 46         =>   x+y = 23  

x²+y² = 17² = 289  

now (x+y)² = 23² 

=> x²+y²+2xy= 529 

=> 289+ 2xy = 529

=> xy = 120  

area = xy = 120 sq.cm