Circles have different angle properties described by different circle theorems. Circle theorems are used in geometric proofs and to calculate angles. Circles have different angle properties, described by **theorems**. There are seven circle theorems. An important word that is used in circle theorems is **subtend**, meaning an angle created by an object at a given point.

**1) Angles at the centre and circumference**

**7) The alternate segment theorem**

**Exercise 1**** | Answer Keys**

**Exercise 2**

**| Answer Keys**

**Circle Theorems** – exam-styled questions (PDF)