Question

Find the lateral area of a right circular cone whose radius is 6 feet and height is 8 feet.

Answer 1

Answer:

we know that

[the lateral area of a right circular cone]=pi*r*l

where

r--------------> the radius of the circle part of the cone

l--------------> the side (slant height) of the cone

r=6 ft

h=8 ft

Step 1

find the slant height of the cone

which is determined by using Pythagoras, since the cross section is a right triangle.

l² = h²+ r²------------> l²=8²+6²-------> l²=64+36---------> l=10 ft

Step 2

find the lateral area

[the lateral area of a right circular cone]=pi*r*l--------> pi*6*10----> 188.4 ft²

the answer is 188.4 ft²