Answer:
The height = 4 m answer (B)
Explanation:
∵ The volume of any prism = base area × height
∵ The base is a right angle Δ with 3 and 5
∴ Area the base = 1/2 × 3 × 5 = 7.5 m²
∵ the volume of it = 30 m³
∴ 30 = 7.5 × height
∴ The height = 30 ÷ 7.5 = 4 m