To find the surface area of a cone, we need to add the area of the base (πr^2) and the lateral surface area (πrl).
Given:
r = 9
l = 21
Base area = π(9)^2 = 81π
Lateral surface area = π(9)(21) = 189π
Total surface area = Base area + Lateral surface area
Total surface area = 81π + 189π = 270π
To find the surface area to the nearest tenth, we need to calculate the value of 270π.
Using 3.14159 as the value of π:
270 * 3.14159 = 848.2303
Therefore, the surface area of the cone to the nearest tenth is 848.2 cm².
What is the surface area of the cone to the nearest tenth? The figure is not drawn to scale.
R=9
l=21
(1 point) Responses 207.0 cm2 207.0 cm 2 1,442.0 cm2 1,442.0 cm 2 848.2 cm2 848.2 cm 2 229.5 cm2 229.5 cm 2 Skip to navigation
1 answer