Question

if diagonal of a square is 12cm, then its area is​

Answer 1

Answer:

length × length =area of square

12 × 12 = 144

answer = 144 cm

Answer 2

Answer: 72 cm2

Step-by-step explanation:

Diagonal = 12 cm

Using Pythagoras Theorem

(AC)2 = (AD)2 + (DC)2

(12)2 = (AD)2 + (DC)2

144 = (AD)2 +(AD)2 (because all sides of square are equal)

144 = 2×(AD)2

(AD)2 = 144 ÷ 2

AD = √72

AD = 6√2cm

AD = AB = BC = CA = 6√2cm

Area of Square = (SIDE)2

= (6√2)2

= 36 × 2

= 72 cm2

Hope you have got your Answer!

Pleased to solve your doubts.

Note : 2 × AD (This is 2 times AD)

(AD)2 (This is AD square)