If the angles of triangle ABC are in increasing order and in an arithmetic progression then find sinB
the angles A,B,C are
x, x+y, x+2y
They sum to 180, so
3x+3y = 180
x+y = 60
angle B is x+y, so ...
x, x+y, x+2y
They sum to 180, so
3x+3y = 180
x+y = 60
angle B is x+y, so ...