Question

if A,B and C are interor angles of theABC tyen show that sin (B+C/2= cos A/2​

Answer 1

Step-by-step explanation:

Sin[(B+C)/2]

Since A+B+C=180 for interior angles of triangle ABC.

then B+C=180-A.

NOW Sin [(180-A)/2]

=Sin[90-(A/2)] since Sin(90-A)=CosA

=Cos(A/2)

make me breanlyst answer