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?

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