Question 15
Mensuration of SolidsThe cross section of a uniform prism is a right-angled triangle with sides 3 cm, 4 and 5 cm. If its length is 10 cm, calculate the total surface area.
- A.142 cm2
- B.132 cm2
- C.122 cm2
- D.112 cm2
Show the answer and explanation
Answer: B (132 cm2)
Explanation
Two triangles: 2 × ½ × 3 × 4 = 12 cm2. Three rectangles: 10 × 3 + 10 × 4 + 10 × 5 = 120 cm2. Total = 132 cm2.