Circle Theorems Rules Flashcards
1
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Theorem 1
Angles subtended of the diameter will be 90° at the circumference.
2
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Theorem 3
Angles subtended of the same arc will be the same at the circumference.
2
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Theorem 2
The angle subtended at the centre is double the angle at the circumference.
2
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Theorem 4
Opposite angles in a cyclic quadrilateral add to 180°
(a cyclic quadrilateral refers to a quadrilateral in a circle only)
2
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Theorem 5
A radii of a circle and a tangent line will meet at a 90° angle.
3
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A
Circle Theorem 7
Alternate Segment Theorem
Not required explanation: The angle created by the meeting of a tangent and a chord will be the same as the angle subtended of that chord at the circumference.
3
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Circle Theorem 6
If the radius of a circle bisects a chord. Then where they meet it will be a 90°.
3
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