We know that the distance from the centroid of the triangle to one of the vertices is the radius of the circle required to inscribe an equilateral triangle.
[distance centroid of the triangle to one of the vertices]=(2/3)*h h=the altitude of the equilateral triangle-----> 21.65 cm so [distance centroid of the triangle to one of the vertices]=(2/3)*21.65 [distance centroid of the triangle to one of the vertices]=14.43 cm
the radius is equal to the distance of the centroid of the triangle to one of the vertices hence the radius is 14.4 cm
