Question

The area of paper needed to create 25 paper toys in the shape of pentagonal pyramid with the below dimensions is sq cm

• A. 382.5
• B. 457.5
• C. 580.5

Answer 1

The correct option is A 382.5

The given pyramid contains one pentagonal base and 5 triangular faces.

Total surface area = base area + area of 5 triangular faces.


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

Base of the triangle = 9 cm
Height of the triangle = 10 cm

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

= $\frac{1}{2}$ $\times$9 $\times$ 10 = 45 sq cm


Total area of 5 triangular faces = 5 $\times$ 45 = 225 sq cm


Base area = 157.5 sq cm

Total surface area of the pentagonal pyramid = Base area + Area of the 5 triangular faces

= 157.5 + 225 = 382.5 sq cm

Hence, the total surface area of paper needed = 382.5 sq cm