An open cone with base radius 28cm and perpendicular height 96cm was stretched to form sector of a circle. calculate the arc of the sector (Take \(\pi = \frac{22}{7}\))
-
8800cm2
- 8448cm2
- 4400cm2
- 4224cm2
The correct answer is: A
Explanation
L2 = 962 + 282= 9216 + 784
= 10000
L = \(\sqrt{10000}\)
= 100cm
curved surface area = \(\pi r l\)
= \(\frac{22}{7} \times 28 \times 100\)
= 8800cm2
area of cone = area of sector
area of sector = 8800cm2