Answer:
first one:
Area of a circle = π*r²
diameter (they gave) = 30ft
radius = diameter/2 = 15ft
π*15²= 706.85834705770347865409476123789
to nearest tenth= 706.9 ft
second question:
circumference = 2*π*r or d(diameter)*π
diameter = 30ft
30*π = circumference = 94.247779607693797153879301498385
in terms of π = 30π