Answer:
19.63
Explanation:
area =

where r is the radius.
The diameter is double the radius.
So divide the diameter by 2 to find the radius.
5/2 = 2.5
Now plug into the area formula and solve.
area =

area =6.25
area = 19.6349540849
The problem didn't say anything about what to round to. If you round to the hundredths place, this would be 19.63.