The total surface area (Total SA) of a cone is : Lateral SA + base SA
Lateral SA=πrt
base SA=πr²
Total SA=πrt + πr²=πr(t+r)
Data:
t=10 in.
r=8 in.
Total SA=π(8 in)(10 in + 8 in)=8π in(18 in)=144π in².
Answer: the total surface area of this cone is 144π in².