## Section C - Surface Geometry

Section C contains 5 topics from which you choose 2 to study.

Each question is worth

Each question should take you

This page looks at the Surface Geometry option.

Each question is worth

**45 marks**(out of 400 for total DCG grade)Each question should take you

**35 minutes**This page looks at the Surface Geometry option.

**Skills you will need**:- Finding a dihedral angle (there are two methods, pick your preferred one and stick with it)
- Using a dihedral angle, work back and find a missing height
- Find the true shape of a surface (know a few ways to do this; rotation, auxiliary, combining true lengths)
- Find true lengths (by rotating and auxiliaries)
- Find the traces of a plane (hard to picture, easy to do)
- Develop a cylinder and a cone with a cut
- Use and/or find the
*pitch*of a roof