Formulas for Circumradius

Ratio of inradius to circumradius in triangle

In an equilateral triangle, inradius r , circumradius R and ex-radius r_1 are in A.P. (b) G.P. (c) H.P. (d) none of these

Half angle formulae| Area of triangle inradius| Circumradius and exradii

In an equilateral triangle,the in-radius and circumradius are in the ratio

In a right - angled isosceles triangle , the ratio of the circumradius and inradius is

In a right angled isoceles triangle,the ratio of the circumradius and inradius is

In a right-angled isosceles triangle, the ratio of the circumradius and inradius is