JAMB Mathematics 1987 Question 43

Question 43

Mensuration of Solids

The base of a pyramid is a square of side 8cm. If its vertex is directly above the centre, find the height, given that edge is 4√3cm

  1. A.6cm
  2. B.5cm
  3. C.4cm
  4. D.3cm
Show the answer and explanation

Answer: C (4cm)

Explanation

Half the diagonal of the base is 8√2/2 = 4√2. Height² = (4√3)² − (4√2)² = 48 − 32 = 16, so the height is 4cm.