If A, B and C are the vectices of a triangle ABC, then prove sine rule `a/sinA=b/sinB=c/sinC`

If A ,Ba n dC are the vetices of a triangle A B C , then prove sine rule a/(sinA)=b/(sinB)=c/(sinC)dot

If A , B and C are interior angles of triangle ABC ,then show that sin ((B+C)/( 2) )=cos (A) /(2)

If A,B,C, are the angles of a triangle such that cotA/2=3tanC/2, then sinA ,sinB ,sinC are in AdotPdot (b) GdotPdot (c) HdotPdot (d) none of these

In a triangle ABC, prove that b^(2) sin 2C+c^(2) sin 2B=2bc sin A .

BE and CF are two equal altitudes of a triangle ABC. Using RHS congruence rule, prove that the triangle ABC is isosceles.

In A B C , the three bisectors of the angle A, B and C are extended to intersect the circumeircle at D,E and F respectively. Prove that A DcosA/2+B EcosB/2+C FcosC/2=2R(sinA+sinB+sinC)

In a triangle ABC, prove that (b + c)/(a) le cosec.(A)/(2)

If I is the incenter of a triangle ABC, then the ratio I A : I B : I C is equal to a) cos e c A/2: cos e c B/2: cos e c C/2 b) sinA/2:sinB/2:sinC/2 c) secA/2:secB/2:secC/2 d) none of these

Let a,b,c be the sides of a triangle ABC, a=2c,cos(A-C)+cos B=1. then the value of C is

IF in a Delta ABC , the altitudes from the vertices A,B,C on opposite sides are in H.P , then sin A , sin B , sin C are in