A cone has a base radius of 8cm and height 11cm. calculate , correct to 2d.p, the curved surface area
A
341.98cm\(^2\)
B
276.57cm\(^2\)
C
201.14cm\(^2\)
D
477.71cm\(^2\)
Verified Correct Answer: A.
Step-by-Step Mathematical Solution
Where l\(^2\) = h\(^2\) + r\(^2\)
l\(^2\) = 11\(^2\) + 8\(^2\)
l = \sqrt185
l = 13.60cm
The formula of CSA of Cone is \pirl
\(\frac{22}{7}\) * 8 * 13.60
= 341.979 or 341.98 (2d.p)
Source: WAEC / JAMB / NECO Classroom Archive (Record #61426)