Question

The diagram shows an incomplete polygon. How do I determine whether it is a regular polygon or not? How should I write my reasoning?​

Answer 1

see explanations below.

Explanation:

The shown sides are all equal.

If it is a regular polygon, it must have all interior angles equal, and all sides equal.

IF

all sides are equal and all angles are equal,

THEN

it is a regular polygon, with 12 sides, because in regular polygons, all exterior angles are equal, and add up to 360 degrees.

No. of sides = 360/(180-150) = 360/30 = 12 sides.