What is the measure of <4?

Given: pqrs is a parallelogram prove: pr and qs bisect each other at t

Rhombus adef is inscribed into a triangle abc so that they share angle a and the vertex e lies on the side bc . what is the length of the side of the rhombus if ab=c, and ac=b.

If two points are given, then exactly one line can be drawn through those two points. which geometry term does the statement represent