Question

Find the total surface area of the following cone. leave your answer in terms of pi.

Answer 1

Answer:

90pi

Step-by-step explanation:

SA = pi r l +B

we know the radius is 5

We need to find the slant height using the Pythagorean theorem

a^2+b^2 = c^2

5^2+12^2 = l^2

25+144= l^2

169 = l^2

Taking the square root of each side

sqrt(169) = sqrt(l^2)

13 = l

B is the area of the base

B = pi r^2 = pi (5)^2 = 25 pi

SA = pi r l +B  = pi (5)*13 + 25pi

                       =65pi +25pi = 90pi