Question

please solve the problem​

Answer 1

Answer:

for a triangle angles a+ b+c=180

dividing by 2

a/2 +b/2 +c/2=90

b/2+c/2=90- a/2

taking sin on both sides

sin(b+c/2)=sin(90-a/2)

sin(b+c/2)=cosa/2

because sin(90-theta)=cos theta

Answer 2

Answer:

sorry I don't know i will answer next time