Question

Find the missing measure for a right circular cone given the following information.

Find r if T.A. = 12 and L.A. = 8.

2
4
16

Answer 1

I'm going to assume TA is short for "total area" (more commonly known simply as the surface area of the cone) and LA is short for "lateral area"... where lateral area is the surface area of the cone minus the area of the circular area on the end?

TA = area of circle + LA
12pi = area of circle + 8pi
4pi = area of circle

Not sure what the "missing" measure is you're looking for here... but since 4pi isn't one of the possible answers, I'm going to assume you're looking for the radius r.

area of circle = 4pi
(pi)(r^2) = 4pi
r^2 = 4
r = 2

Answer a.

Answer 2

thanks zoe

Answer 3

np anne :D