Circle theorems are a set or rules you can use to arrive at the correct value of angles in a circle. In this article we will look at theorems 1 to 3, with the remaining being discussed in a sperarate article.

**RULE 1:** If you have 2 angles coming from **THE SAME ARC** (as shown below) –> Angle **at CENTRE** = TWICE angle **at CIRCUMFERENCE**

**RULE 2:** Angles **IN A** **SEMI CIRCLE** have a 90° angle

**RULE 3:** Angles **AT THE CIRCUMFERENCE** coming from the **SAME ARC** are equal

Circle theorems are a set or rules you can use to arrive at the correct value of angles in a circle. In this article we will look at theorems 1 to 3, with the remaining being discussed in a sperarate article.

RULE 1:If you have 2 angles coming fromTHE SAME ARC(as shown below) –> Angleat CENTRE= TWICE angleat CIRCUMFERENCERULE 2:AnglesIN ASEMI CIRCLEhave a 90° angleRULE 3:AnglesAT THE CIRCUMFERENCEcoming from theSAME ARCare equal## Nouri Dib