Triangle ABC has equilateral triangles drawn on its edges. Points P, Q and R are the centres of the equilateral triangles. What can you prove about the triangle PQR?

You can change triangle ABC below by dragging the vertices and observe what happens to triangle PQR.

NOTES AND BACKGROUND

There are many ways of proving this result. One way you might like to try involves tessellation.

For an animated proof of Van Aubel's Theorem see http://agutie.homestead.com/files/vanaubel.html