The sides of a triangle are 25, 39 and 40 units of length.

Find the diameter of the circumscribed circle.

2D shapes and their properties. Cartesian equations of circles. Triangles. Creating and manipulating expressions and formulae. Sine, cosine, tangent. Angles - points, lines and parallel lines. Regular polygons and circles. Sine rule & cosine rule. Pythagoras' theorem. Circle properties and circle theorems.