Sine and Cosine Law

Circle Theorems

Inverse of a Function

Circle Theorem (Exercises)

Fractions

Quadratic Function Solver

This widget may help you to check your an during your revision.

SYSTEM OF LINEAR EQUATIONS

Circle Theorems

Circles and Angles 1

Compare the angle at the centre to the angle on the circle. Move the points and become familiar with different versions of the diagram.

Circles and Angles 2

Compare the angle at the centre to the angle on the circle (obtuse and reflex angles). Move the points and become familiar with different versions of the diagram.

Circle Theorems - angles on the same arc

Investigate angles on the same arc. Move the points - what do you notice?

Angle in a Semi-circle 1

Move point A or D. What do you notice about the angles?

Angle in a Semi-circle 2

Angle in a semi-circle -proof.

Circle theorems - Cyclic Quadrilaterals

Move point A or C. What do you notice about the angles? Move point B or D. What do you notice? Can you explain these results?

Circle theorems - Cyclic quadrilaterals

Look at the angles on each arc separately. Look at both at the same time and move the points. What do you notice?

Cyclic Quadrilateral 3

This shows how both pairs of opposite angles in a cyclic quadrilateral sum to 180°

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