What can you say about the tangents of the angles at the centre of the circle?

Alternatively, can you see how you might calculate the area of these 6 smaller triangles?

Visualising. Circle properties and circle theorems. Sine, cosine, tangent. Creating and manipulating expressions and formulae. 2D shapes and their properties. Pythagoras' theorem. Area - triangles, quadrilaterals, compound shapes. Regular polygons and circles. Angles - points, lines and parallel lines. Trigonometric identities.