+1234 Points $A$, $B$, and $C$ are on a circle such that $AB = 8$, $BC = 15$, and $AC = 12$. Find the radius of the circle.
+129771 ABC will form a triangle and the circle is the circumcumcircle of the triangle
radius = [product of the sides ] / [4 area ]
semiperimeter = [ 8 + 15 + 12 ] / 2= 17.5
Area = sqrt [ 17.5 ( 9.5) (2.5) (5.5) ]
radius = [ 8 * 12 * 15 ] / [ 4 sqrt [ 17.5 (9.5)(2.5)(5.5) ] ] ≈ 7.53
