Part a) Find the lateral area
we know that
lateral area=perimeter of the base*height
perimeter of the base=2*pi*r
for r=2.5 ft
pi=3.14
perimeter of the base=2*pi*2.5----> 15.7 ft
height=7.5 ft
so
lateral area=15.7*7.5-----> 117.75 ft²
the answer Part a) is
the lateral area is 117.75 ft²
Part b) find the surface area
surface area=lateral area+2*[area of the base]
area of the base=pi*r²
for r=2.5 ft
area=pi*2.5²-----> 19.625 ft²
surface area=117.75+2*19.625-----> 157 ft²
the answer Part b) is
the surface area is 157 ft²