Question

The base of a right pyramid is a square of side 40 cm long. If the volume of the pyramid is 800 cm³, then its height is:

(a) 5 cm 

(b) 10 cm 

(c) 15 cm 

(d) 20 cm

Answer 1

Answer: (c) = 15 cm

Area of the base = 40 cm × 40 cm = 1600 sq. cm.

Volume of pyramid = \(\frac{1}{3}\)× Area of base × height 

⇒ 8000 = \(\frac{1}{3}\) × 1600 × h 

⇒ \(h= \frac{8000\times3}{1600}\)

= 15 cm.