what are r1 , r2 & r3 represented for?

how can we use sine rule in other triangles?

Dear nithin

r1 represent the radius of circle that is tangent to qpposite side and also tangebt to exended side as shown in diagram

similerly r2 and r3 .

let lenghth of side aposite to angle A,B,C are a,b,c respectivily

then sine rule is

Sin A  /a =SinB  /b  =Sin C /c

Regards

Badiuddin