Geometry

Question Analysis:
This question is about a real-world task — painting a pipe.
The main focus is calculating total surface area when given diameter.

Key Concept Explanation:
Use r = d ÷ 2. Then use A = 2πr² + 2πrh.

Step-by-Step Solution:
r = 5 ft (since diameter = 10 ft), h = 18 ft
2πr² = 2π × 25 = 50π
2πrh = 2π × 5 × 18 = 180π
Total = 50π + 180π = 230π

Common Mistakes...