Three non-overlapping regular plane polygons, at least two of which are congruent, all have side length 1. The polygons meet at a point A in such a way that the sum of the three interior angles at A is 360. Thus the three polygons form a new polygon with A as an interior point. What is the largest possible perimeter that this polygon can have?
a) 12 b) 14 c) 18 d ) 21 e)24
The answer is d)21 but I think I can make all of them, if not more.
Could someone please take a look at my attached work and
show me what I am not understanding?