Please help me please please

Answer:
1276.19553 [tex]m^{2}[/tex]
Step-by-step explanation:
First, find height using Pythagoras thorem.
a=[tex]\sqrt{20^2+12.5^2}[/tex]
a=15.61
Then use the formula to find the surface area of a cone.
π•12.5•(12.5+[tex]\sqrt{15.61^2+12.5^2}[/tex])=1276.19553 [tex]m^{2}[/tex]