I have two equilateral triangles, one pointing up and one pointing down.
The smaller triangle is placed on top of the larger triangles in such a way that the region where they overlap is hexagonal.
What is the perimeter of the overlapping region if:
- The triangles have perimeter 8 and 10?
- The triangles have perimeter x and y?
- (Harder) What constraint must there be on the sizes of the triangles to ensure that it is possible for the shape of the overlapping region to be hexagonal?
