Question

Prove Angle 1 is equal to angle 2 in an series progression
Wisest explanation will be marked as brainiest

Answer 1

Only if one of the angles is  π/3 ( 60°).

Since the (arithmetic) mean of three angles must be the same as the middle angle, and the angles of a triangle add up to  π  ( 180° ), this is necessary. On the other hand, it is also sufficient; the smallest angle is less than the mean by as much as the largest angle is greater than the mean, so we have an A.P. as long as the mean angle (which can only be  π/3 ( 60° )) is the middle angle, which really only means that it is one of the angles.