# Circle Theorems

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• Created by: xxSonia
• Created on: 11-04-14 16:06
Angle at centre
The angle at the centre is twice the angle at the circumference
1 of 7
Angles is a semi-circle
The angle at a circumference in a semi-circle is 90'
2 of 7
Angle is the same segment
Angles in the same segment of a circle are the same to each other
3 of 7
The opposite angles in a cyclic quadrilateral add up to 180 degrees
4 of 7
Tangent
The angle made by a tangent and the radius is a right angle
5 of 7
Alternate Segment
The angle between a tangent and a chord at the point of contact is equal to the angle made by the chord in an other segment off the circle
6 of 7
Two tangents
From any point outside the circle, you can only draw two tangents to the circle, and theses tangents will be equal in length
7 of 7

## Other cards in this set

### Card 2

#### Front

Angles is a semi-circle

#### Back

The angle at a circumference in a semi-circle is 90'

### Card 3

#### Front

Angle is the same segment

Tangent