Question

why are some triangles not 360° when adding all of the interior angles?

Answer 1

The answer I thought of is that all triangles add up to the same number of degrees because any triangle is a "variant" of an equilateral triangle, that adds to 180. When you deform it (by stretching it and changing its angles), one side may get a bigger angle, but that means the others get smaller angles.

(sum of exterior angles 360)

Answer 2

I know but the above person has given the answer