What is the surface area of the cone? Express your answer in terms of π.

surface area of a cone = 132.935πft

Step-by-step explanation:

to find the surface area of a cone

given that

radius = 5ft

height of cone = 21ft

recall that the formulae for finding the surface area of a cone = πr( r + √ h² + r²)

so,

surface area of a cone = πr( r + √ h² + r²)

surface area of a cone = π x 5( 5 + √ 21² + 5²)

surface area of a cone = 5π ( 5 + √ 441 + 25)

surface area of a cone = 5π( 5 + 21.587)

surface area of a cone = 5π (26.587)

surface area of a cone = 132.935πft

you need to rotate this triangle about the origin 270 degrees clockwise to create the full square.