This problem brings together ideas of areas of circles and squares, the use of Pythagoras' Theorem and the property of tangents to a circle from an exernal point.

You might start with the middle diagram which is the easiest. It brings in the ratio of the sides of an isosceles right angles triangle which is again used in the other two parts.

If you know the side length of an isosceles right angled triangle how do you find the hypotenuse?

Which lengths are equal in the diagram?

Which angles are equal?

Can you use the symmetry of the diagram?

Cartesian equations of circles. Pythagoras' theorem. Sine, cosine, tangent. Sine rule & cosine rule. Regular polygons and circles. Area - squares and rectangles. 2D shapes and their properties. Circle properties and circle theorems. Mathematical reasoning & proof. Area - circles, sectors and segments.