I think the image you were referring to is this:
This image shows two triangles that intersect each other at a common angle. The two triangle are triangle PQT and triangle RSQ. Both triangles meet at a common angle, and that is angle Q, or in other words, angle PQR
This image shows two triangles that intersect each other at a common angle. The two triangle are triangle PQT and triangle RSQ. Both triangles meet at a common angle, and that is angle Q, or in other words, angle PQR