Question

The radius and slant height of the cone are multiplied by 1/3. Describe the effect on the surface area.

Radius= 4
Slant height= 12

A. The Surface area is multiplied by 1/3
B. The Surface area is multiplied by 1/9
C. The Surface area is multiplied by 16/3
D. The Surface area is multiplied by 16/9

Can you explain in detail how you got the answer please :)

Answer 1

just substitute it to the formula

Answer 2

S=piRL+piR^2

Answer 3

S=piR1/3(1/3*L)+pi(R*1/3)^2

Answer 4

the new surface area then is 9 times smaller than previous

Answer 5

the answer will be B