Property 1 : Angle subtended at the Centre of a circle is twice the angle subtended at the circumference.

Property2 : Angles subtended by an arc in the same segment of a circle are equal.

Property 3 : The opposite angles in a cyclic quadrilateral add up to 180 degrees- the angles are supplementary.

Property4 : The angle in a semi-circle is a right angle.

Property 5: The angle between a tangent and the radius drawn to the point of contact is 90 degrees.

Property6 : From any point outside a circle just two tangents to the circle may be drawn and they are of equal length.

**Property 1 : **Angle subtended at the Centre of a circle is twice the angle subtended at the circumference.

**Property2 :**

Angles subtended by an arc in the same segment of a circle are equal.

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#### Interactive Graph : 2

**Property 3 :**

The opposite angles in a cyclic quadrilateral add up to 180 degrees- the angles are supplementary.

**Property 4:** The angle in a semi-circle is a right angle

**Property 5:** The angle between a tangent and the radius drawn to the point of contact is 90 degrees.

**Property 6 :** From any point outside a circle just two tangents to the circle may be drawn and they are of equal length.

**Skill builder questions**

Practice Worksheet – 1 |
Circle theorem ws – 1 | Answers |

Practice Worksheet – 2 | Circle theorem ws – 2 |
Answers |