Question

The dimensions of the roof of a toy house are given below. Find the surface area.

• A. 144 sq cm
• B. 290 sq cm
• C. 480 sq cm
• D. 380 sq cm

Answer 1

The correct option is C 480 sq cm

The given square pyramid contains one square base and 4 triangular faces.

Total surface area = Base area + 4 $\times$ area of one triangular face

Area of triangular face = $\frac{1}{2}$$\times$ base $\times$ height

Base of the triangle = 12 cm
Height of the triangle = 14 cm

Area of triangular face = $\frac{1}{2}$$\times$ 12 $\times$ 14

= 84 sq cm

Total surface area = 144 + 4 $\times$ area of one triangular face

= 144 + 4(84) = 144 + 336

= 480 sq cm

Hence, the total surface area of the roof of the toy house = 480 sq cm.