Theorem 4 :`sinA+sinB+sinC=4cosA/2cosB/2cosC/2`

If A+B+C=180 , prove that: sinA+sinB+sinC=4cosA/2cosB/2cosC/2

If A+B+C=pi , prove that : sinA+sinB+sinC= 4cos( A/2 )cos( B/2) cos(C/2)

In DeltaABC , prove that: sinA+sinB-sinC=4sinA/2sinB/2cosC/2

If A+B+C=pi/2 , prove that: sin2A + sin2B+sin2C = 4cosA cosB cosC

In a DeltaABC , if a = 18, b = 24, c = 30, find (i) sinA, sinB, sinC (ii) cosA, cosB, cosC

In DeltaABC ,prove that: sin2A + sin2B-sin2C=4cosA cosB sinC

If A+B+C=pi , prove that : cosA sinB sinC +cosB sinC sinA+cosC sinA sinB=1+cosA cosB cosC .

If A+B+C = pi , prove that : cosA- cosB - cosC = 1-4sinA//2cosB//2cosC//2 .

In triangleABC , which is not right angled, if p=sinA sinB sinC = and q=cosA. cosB. cosC. Then the equation having roots tanA,tanB and tanC is

If (1+sinA)(1+sinB)(1+sinC)=(1-sin-A) (1-sinB)(1-sinC)," then prove that "(1+sinA) (1-sinB)(1-sinC)=pmcosA.cosB.cosC .