A prism has an equilateral triangular base with a side length of 4 cm. Its height starts at 5 cm and increases by 1 cm for each subsequent layer, forming 5 layers in total. What is the total volume of the prism? (Use = 1.732)
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. 242.48 cm3.
Base area of equilateral triangle = (√3/4) × side2
= (1.732/4) × 42
= 0.433 × 16
= 6.928 cm2
Heights of 5 layers: 5 cm, 6 cm, 7 cm, 8 cm, 9 cm
Total height = 5 + 6 + 7 + 8 + 9 = 35 cm
Volume = Base area × Total height = 6.928 × 35 = 242.48 cm3