You may also like

Degree Ceremony

What does Pythagoras' Theorem tell you about these angles: 90°, (45+x)° and (45-x)° in a triangle?


Ten squares form regular rings either with adjacent or opposite vertices touching. Calculate the inner and outer radii of the rings that surround the squares.

Ball Bearings

If a is the radius of the axle, b the radius of each ball-bearing, and c the radius of the hub, why does the number of ball bearings n determine the ratio c/a? Find a formula for c/a in terms of n.

Geometric Trig

Age 16 to 18 Short Challenge Level:

This problem uses basic notions of trigonometry and areas of triangles which are fundamental to developments in A-level mathematics.
Being able to work with diagrams such as this is useful prepation for both coordinate geometry and mechanics.