Can I find out the angles of a rectangle given the sidelengths and that 2 of the sides are parallel?

Question

Not really a big brain when it comes to math.

First question here... hope it meets the standards.

Let's say I've got a quadrilateral, I know the side lengths, and I know two of the sides are parallel. Can I figure out the angles?

Answer 1

A quadrilateral with 2 parallel sides is a trapezoid. Since you know all 4 side lengths you can calculate the length of the diagonals. Select one diagonal and find its length (e.g. use equation 10 in the above link). You now have 2 triangles where all side lengths are known. Finding angles in such triangles is easy.