A circular track of radius 17.5 m is to be covered with a uniform circular band of width 3.5 m to create a jogging path around it. Find the area of the jogging path (the ring-shaped region). (Use π ≈ 3.1416 and provide your answer correct to two decimal places)
Show answer & explanation
Correct answer: B
Explanation
Given:
Inner radius = 17.5 m
Strip width = 3.5 m
π = 3.1416
By formula:
Area of ring = π(R² − r²)
Outer radius R = 17.5 + 3.5 = 21
R² = 21² = 441
r² = 17.5² = 306.25
R² − r² = 441 − 306.25 = 134.75
Area = 3.1416 × 134.75 = 423.33 m²