A cone is made from a sector of circle of radius 14cm and angle of 90o. What is the area of the curved surface of the cone? (Take x = 22/7)
A
22cm2
B
38.5cm2
C
77cm2
D
154cm2
E
308cm2
Verified Correct Answer: D.
Step-by-Step Mathematical Solution
Length of arc = θ/360 * 2πr
=> r = 90/360 * 14/4 = 3.5
slant height t = 14cm
curved surface area of cone = πrl
=> 3.142 x 3.5 x 14 = 153.95
Source: Myschool Past Questions Archive (Record #22192)