Question

find the area of a square whose diagonal is 3.6 m

Answer 1

let, side of square = a

Diagonal = √2 a

3.6 = √2 a

a = 3.6/√2

a = 1.8 √2

Area = a²

        = (1.8√2)²

        = 6.49 m²

Answer 2

diagonal of the square is 3.6m
therefore the hypotenuse of the triangle it forms is 3.6m
by pythagoras theorem,
h^2=b^2+a^2
3.6=√2x
x=3.6/√2
that is the side of the square is 3.6/√2 m.
therefore area of the square=side*side=3.6/√2*3.6/√2=12.96/2=6.48
the area is 6.48m^2