G1 Circle Theorems Flashcards
Which theorem links angles at the centre and angles at the circumference?
Angle at the centre is always twice the angle at the circumference.
Which theorem involves angles joined by the same arc?
Angles joined by the same arc are equal.
What is a cyclic quadrilateral and what is the theorem to do with it?
A quadrilateral with all four vertices on the circumference of a circle.
Opposite angles of a cyclic quadrilateral add up to 180 degrees.
What is a tangent?
A straight line that horizontally meets the circumference of a circle.
What size is the angle between a tangent and the radius of a circle?
A right angle (90)
What is the alternate segment theorem?
An angle on the other side of a line and at the opposite end will be the same size as the angle on the other side of the line. (Draw)
What is a chord?
A straight line joining two points on the circumference of a circle, dividing a circle into two segments.
