ART Rachaunn is laying out a pattern for a stained glass window. So far he has placed the 13 regular polygons shown. Find the measure of each angle at the circled vertex. Then find the sum of the angles.

Answer:
180 degrees in a triangle so as triangle is equilateral that angle would be 180/3= 60 degrees
360 degrees in a square. 4 angles in a square. 360/4= 90 degrees
720 degrees in a hexagon. 6 angles in a hexagon. 720/6 = 120 degrees
360 degrees around a point.
so the answer is d.