An isosceles triangle ABC is inscribed in a circle with center O. If AB = BC = 13cm and BC = 10 cm, find the radius r of the circle in cm.
on your sketch, draw in the long altitude of the triangle ... note that its length is 12.
also draw in the radii, length , from each corner of the triangle.
let = perpendicular distance from the short side (10) to the circle center.
two equations can be formed ...
doing the substitution ...