Question

The diagonal of a square is 12cm long find its area and perimeter

Answer 1

Diagonal = √2side of square
let side be = a
12 = √2a ( Diagonal = √2 side)
12/√2 cm = a
Perimeter = 4 x side
= 4 x a
= 4 x 12/√2
= 48/√2
= 48√2/2. (multiplying numerator and denominator by √2)
= 24√2
Area = Side x Side
= 12/√2 x 12/√2
= 144/2
= 72 cm sq.

Answer 2

Area=1/2*12*12
72cm^2
Side of square=root of 72=8.4
Perimeter =8.4*4=33. 6cm
Area = side * side
=8.4*8.4=70.56sq cm