The area of an ellipse is 132cm\(^2\).The length of its major axis is 14cm.Find the length of its minor axis
A
10.5cm
B
5cm
C
10cm
D
12cm
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
To find the minor axis of an ellipse:
Given:
- Area \(A = 132 \, \text{cm}^2\)
- Major axis = \(14 \, \text{cm}\)
Semi-major axis:
\(a = \frac{14}{2} = 7 \, \text{cm}\)
Area formula:
\(A = \pi \times a \times b \implies 132 = \pi \times 7 \times b\)
Solving for \(b\):
\(b = \frac{132}{\pi \times 7} \approx \frac{132}{21.98} \approx 6 \, \text{cm}\)
Length of minor axis:
\(\text{Minor axis} = 2b \approx 2 \times 6 = 12 \, \text{cm}\)
Source: Myschool Past Questions Archive (Record #41286)