Question

Diagonal of a square is 6cm then what is area of square

Answer 1

According to the property of square, the diagonal bisects the angle and so you get 45 - 45 - 90 degree triangle.

Use a sin45 or cos45 in the triangle you will get the length of the square as 6 / √2 cm . Then use the formula of area of a square as L×L ie. 6/√2 × 6/√2 = 216!!!

Answer 2

Let side of the square =a

Then by pythagorean theorem

diagonal²=side² +side²

6²=2a²

a²=6²/2  [a²=area of square]

area =36/2=18cm²