In any Δ ABC, 2R2 sin A sin B sin C is equal to
2∆
3∆
∆
∆/2
We have, 2R2 sin A sin B sin C
=2R2a2R.b2R.c2R(∵a2sinA=b2sinB=c2sinC=R)⇒abc4R=Δ
In any ΔABC,1r1+1r2+1r3 is equal to