Question 990516
The radius, {{{r}}} , of a circle is the distance between any point on the circumference, and the center of the circle.
In this case, the point (3,7) must be at a distance {{{r}}} from point (8,2), and
{{{r^2=(8-3)^2+(2-7)^2=5^2+(-5)^2=25+25=50}}} .
The area of a circle with radius {{{r}}} is {{{pi*r^2}}} ,
so the area of the circle in the problem is
{{{pi*50= highlight(about 170.8)}}} (rounded to the nearest tenth of a square unit).