9. If the diagonal of a square is 12 centimeters, the area of the square is

A. 102 cm2.

B. 36 cm2.

C. 144 cm2.

D. 72 cm2.

D. 72 cm²

Step-by-step explanation:

The area of a square is given by;

Area = l² where l = length

Given that the diagonal is 12 cm, let assume length of the square to be l

Apply the Pythagorean relationship where a=b=l

l² + l² = 12²

2 l² = 144

l² = 144/2

l² = 72

l = √72 = 8.485 cm

⇒length of the square = l = 8.485 cm

⇒Area of the square = l² = 8.485² = 72 cm²