A circular embankment is constructed with a radius of 40 meters. A second concentric circular embankment is built around the first, with a width of 12 meters. What is the approximate area of the region between the two embankments?
Show answer & explanation
Correct answer: A
Explanation
Given:
Radius of the first circle = 40 meters
Width of the second circle = 12 meters
By the formula:
Area between two concentric circles = π(R² − r²)
Outer radius (R) = 40 + 12 = 52 meters
Area = π(52 × 52 − 40 × 40) = π(1104)
= 1104 × 22 / 7
= 157.714 × 22 = 3470 m²