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

just sum

10 + 10 = 20