Question

the diameter of the base of a right cone is 6 cm. if the total surface area of the cone is 90π cm^2, what is the length of the slant height? a.) 6.6 cm. b.) 9 cm. c.) 21 cm. d.) 27 cm. could i have the formula to solve this problem?

Answer 1

Radius = diameter/2 = 6 cm/2 = 3 cm


`Area= \pi r(r+s) \\ 90 \pi = 3\pi (3+s) \\ 30=3+s \\ s=30-3=27cm`