You are making conical party hats with a height of 5.5 inches and a diameter of 3.5 inches. About how much cardboard is needed for each hat? Round your answer to the nearest hundredth.

Question

You are making conical party hats with a height of 5.5 inches and a diameter of 3.5 inches. About how much cardboard is needed for each hat? Round your answer to the nearest hundredth.

Answer 1

You need to find the surface area of the conical figure

That is PI* R * (slant height + R)

R is 1/2 of 3.5 = 1.75

Height, radius and slant height form a right triangle with the radius and height as legs, so slant height is the hypotenuse and can be determined using the Pythagorean Theorem.

R**2 + Height**2 = slant height**2, where R = 1.75 and height = 5.5

Once you determine slant height you can plug it into the formula to determine surface are.