If the height of a right circular cone is 24 m and its slant height is 30 m, then what is the area of its curved surface? (Use π = 22/7)
Show answer & explanation
Correct answer: A
Explanation
The correct answer is option 1 i.e. 1697.143 m2.
Given:
Height of a right circular cone is 24 m and its slant height is 30 m
Formula used:
Curved surface area = πrl, where ----- (1)
r = radius and l = slant height
Calculations:
Using Pythagoras theorem to find the value of radius
⇒ (Hypotenuse)2 = (base)2 + (perpendicular)2
⇒ (30)2 = r2 + 242
⇒ r2 = 900 - 576 = 324
⇒ r = 18
Using equation (1), we get
⇒ (22/7) × 18 × 30 = 1697.143 m2