Question

What is the area of the square below?
16.97
72
144
288

Answer 1

the diagonal of square is a√2
the half of it a√2/2=12
a=12*2/√2=12√2
S=a^2=12√2*12√2=288

Answer 2

We can form an isosceles triangle, given 12cm is from the corner to the centre. Form a line from the centre and construct a diagonal. This is our hypotenuse. Note that the hypotenuse is 24cm.

Let the side be x. Since it's a square, the two remaining sides are x. We can use Pythagoras' theorem to find x.

24² = x² + x² = 2x²
Since, 24² = 2x²; 576 = 2x²
288 = x² and x = √(288)
Therefore A = √(288)·√(288) = 288cm²