Circle theorems

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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

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.

**Theorem 1 :
Angle subtended at the Centre of a circle is twice the angle subtended at the circumference.
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**Theorem 2 :
Angles subtended by an arc in the same segment of a circle **

**This course caters for students who already possess knowledge of basic**

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

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**Theorem 4 :
The angle in a semi-circle is a right angle.
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**Theorem 5:
The angle between a tangent and the radius drawn to the point of contact is 90 degrees.
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**Theorem 6 :
From any point outside a circle just two tangents to the circle may be drawn and they are of equal length.**

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**Skill builder questions
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Practice worksheet – 1 | Circle Theorem worksheet 1 of 4 |

Practice worksheet – 2 | Circle Theorem worksheet 2 of 4 |

Practice worksheet – 3 | Circle Theorem worksheet 3 of 4 Circle theorems – Revision |