# Circle Geometry - angles from a chord

- Author:
- DavidA

**A illustration of the properties of the angles drawn from the ends of a chord in a circle.**Circle Theorems http://www.geogebratube.org/student/c89/m1462/yryy

Two important results are the equality of the

**angles at the circumference**and their connection to the**angle at the centre**. A special case that you are often expected to know is the result when the angle at the centre is 180. When AB becomes a diameter and you have a**semi-circle**.**What is significant about the angle at the circumference in this case?**