formula for inradius

Derive the Formula of inradius (i) Delta/ s (ii) ( s-a) tan A/2 (iii) 4R sin A/2sin B/2sin C/2

Formulae OF inradius(r)||ex-radius(r1,r2,r3)

Find the ratio of circumradius to inradius . If the ratio of sides is 5:7:8 .

In a triangle ABC, if AB=3, BC=4, CA=5. Then the surface area of the sphere having a radius equal to the inradius of the triangle is.

ABC is an isosceles triangle in which AB = AC and (angleA)= 2(angleB) AB = 4 cm . What is the ratio of inradius to the circumradius?

Two sides of triangle ABC are 5 and 12. Area of DeltaABC=30 Find 2R+r where R is circumradius and r is inradius.

If two sides of a triangle are roots of the equation x^(2) -7x + 8 = 0 and the angle between these sides is 60^(@) then the product of inradius and circumradius of the triangle is

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

In an equilateral triangle,if inradius is a rational number then