Are trapezoids always similar

Answer 1

Most of the time trapezoids are similar but in some cases they are not

Depends on what you call "similar." In mathematics, "similar" triangles have the same angles, but differ in size. One might be a shrunken version of the other. In that case, they are usually not. The only requirement for a trapezoid is the four sides with either pair of sides being parallel. So, yes, a square is a trapezoid as well. Try this: Draw two parallel lines. Now draw two lines connecting them anywhere you want. The enclosed area is the trapezoid. Can you see how there are an infinite number of trapezoids you can make?