So the formula for the area or a circle is πr². You however have been given the diameter, (line all the way across the circle) so to work out the radius we would divide 15in by 2 which gives us 7.5. Now we know the radius, it’s just a process of substitution. π x 7.5² = 176.7145867644259. But we need to get this answer in π form. So we divide 176.7145867644259 by π = 56.25π
Answer = 56.25π