Question

5. In a triangle ABC, prove that : cos
(A + B)/2=sin c/2
​

Answer 1

Answer:

Step-by-step explanation:The sum of all angles in a triangle is 180°

Therefore,

A+B+C=180

A+B=180-C

(A+B)/2=(180-C)/2=90-C/2

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