What can be made of two identical triangles?

What can be made of two identical triangles?


Triangle (any isosceles triangle), square (rectangle), diamond
Of course, other strange graphics can also be used



Two identical obtuse triangles can form a parallelogram. Is that right?


Exactly
As long as it is exactly the same triangle, no matter what triangle, can be put together into a parallelogram



Two identical obtuse triangles form a parallelogram whose area is ()


2 times