Synthetic Geometry Proofs:

The following, from Projectmaths.ie are excellent explanations of the Synthetic Geometry Proofs:

**Theorem 11:** If three parallel lines cut off equal segments on some transversal line, then they will cut off equal segments on any other transversal.

http://www.projectmaths.ie/students/cd-strand1and2/docs/THEOREM11.ppsx

**Theorem 12: **Let ABC be a triangle. If a line l is parallel to BC and cuts [AB] in the ratio s : t, then it also cuts [AC] in the same ratio.

http://www.projectmaths.ie/students/cd-strand1and2/docs/THEOREM12.ppsx

**Theorem 13: **If two triangles ABC and are similar, then their sides are proportional, in order:

http://www.projectmaths.ie/students/cd-strand1and2/docs/THEOREM13.ppsx

## Geometry Proofs – 6th Year Higher

**Geometry Proofs – 6th Year Higher**

*Geometry Proofs – 6th Year Higher*