How do you prove a quadrilateral is a trapezium by similarity?

Answer 1

To prove a quadrilateral is a trapezium using similarity, you need to show that one pair of opposite sides is parallel. You can do this by demonstrating that the triangles formed by the non-parallel sides and the segments connecting the endpoints of the parallel sides are similar. If the angles formed by these triangles are equal (due to parallel lines creating corresponding angles), then the sides will be proportional, confirming the similarity. Thus, if you establish similarity in this way, you can conclude that the quadrilateral is a trapezium.