Question

if a b and c are interior angles of a triangle ABC then show that Cos A + B upon 2 is equals to sin C upon 2 ​

Answer 1

Answer:

we know that sum of angles of a triangle = 180

A+B+C =180

A+B = 180-C

divide the above equation by 2

= (A+B)/2 = (180-C)/2

(A+B)/2 = (90-C/2)

multiply the above equation by cos on both sides

cos (A+B/2) = cos(90-C/2)

as we know cos (90-x) = sin x

therefore cos A+B/2 = sin C/2

hope it helps.

Answer 2

Answer:

acha question hai excellent