Question

whats the lateral area of a right circular cone if the diameter of the base is 4 m and the slant height of the cone is 15m? round your answer to the nearest whole number.
a) 214m²
b) 107m²
c) 188m²
d) 94m²

Explanation:

Step1: Find the radius

The diameter \(d = 4m\), so the radius \(r=\frac{d}{2}=\frac{4}{2}=2m\)

Step2: Use the lateral - area formula for a cone

The formula for the lateral area of a cone is \(A=\pi rl\), where \(r\) is the radius and \(l\) is the slant height. Given \(r = 2m\) and \(l=15m\), then \(A=\pi\times2\times15\)

$$A = 30\pi$$

$$A\approx30\times3.14=94.2$$

Answer:

D. \(94m^{2}\)