You may also like

Doodles

Draw a 'doodle' - a closed intersecting curve drawn without taking pencil from paper. What can you prove about the intersections?

Russian Cubes

I want some cubes painted with three blue faces and three red faces. How many different cubes can be painted like that?

Picture Story

Can you see how this picture illustrates the formula for the sum of the first six cube numbers?

Parallel Universe

Age 14 to 16 Challenge Level:

A right-angled triangle ABC is right-angled at B.

An equilateral triangle is constructed on BC.

A line QD is drawn, where Q is the midpoint of AC.

Prove that AB is parallel to QD.