Question

If the length of the diagonal of a square is 20cm , what is the perimeter

Answer 1

We know that if the side of a square is "b" , then its diagonal length is b √2

b√ 2 = 20
b = 10 √2

Perimeter of a square  = 4 times its side = 4 b = 4 (10√2) = 40 √ 2 cm