29. An equilateral triangle of side 10cm is inscribed in a circle. Find the radius of the circle

Answer 1

the altitude of the triangle is 5√3
The altitudes are also medians.
The medians intersect 2/3 of the way from a vertex to the side. That is also the center of the circle.
So, r = 2/3 * 5√3 = 10/√3