Circle Theorems Flashcards
Alternate segment theorem
The angle that lies between a tangent and a chord is equal to the angle subtended by the same chord in the alternate segment
Angles at the centre theorem
The angle at the centre is twice the angle at the circumference
Angles in the same segment theorem
Angles in the same segment are equal
Angles in a semicircle
The angle in a semicircle is 90 degrees
Chord of a circle theorem
The perpendicular from the centre of a circle to a chord bisects a chord into 2 equal parts
Cyclic quadrilateral theorem
The opposite angles in a cyclic quadrilateral total 180 degrees
Tangent of a circle theorem 1
The angle between a tangent and the radius is 90 degrees
Tangent of a circle theorem 2
Tangents which meet at the same point are equal in length