Mensuration Practice Test 1

Diagonal of a square = 18 $\sqrt{2}$
side × $\sqrt{2}$ = $18\sqrt{2}$
side 18 cm
Perimeter of a square = 4 × side = 4 × 18 = 72 cm
Perimeter of triangle = Perimeter of a square 3 × side = 72
Side = $\frac{72}{3}$ = 24 cm
Area of the triangle = $\frac{\sqrt{3}}{4}\times {\left(\mathrm{side}\right)}^2$
= $\frac{\sqrt{3}}{4}\times 24\times 24$ = $144\sqrt{3}$ sq. cm