A right cone has radius 5 ft and slant height 9 ft. The radius and slant height are both multiplied by 1/2. Which of the following correctly describes the effect on the surface area? Help ASAP!!!

a) 15/7

step-by-step explanation:

circle area = pi * radius^2

if diameter = 10 then radius = 5

circle area = pi * 5^2

circle area = pi * 25

circle area = 78.5398163397 square units

step-by-step explanation: