Question

if the angles A,B and C of a triangle ABC are in A.P then find the value of cosB

Answer 1

hope this helps you ....

Answer 2

Answer:0.5

Step-by-step explanation:

Consider the angles such that

A=x-d

B=x

C=x+d

d is the common difference(since the angles are in AP).

Since A+B+C=180degrees

x+d+x+x-d=180

3x=180

x=60 degrees=B

Therefore,

cosB=cos60=0.5.