What shapes can be made by folding an A4 sheet of paper only once?

Mark writes four points on a line at different lengths. What is the distance between the two points furthest apart?

These four touching circles have another circle hiding amongst them...

An equilateral triangle is rolled along a line. What is the length of the path traced out by one of its vertices?

How many triangles can Jack draw with two sides of lengths $6$cm and $8$cm and an area of $7$cm$^2$?

A disc with a pencil inside it is rolled around the outside and inside of a wire equilateral triangle. What shape is drawn by the pencil?

The white square slides once around the pink square. Through what distance does the point P on the white square move?

A snail is at the corner of a cube. What proportion of the cube's surface can the snail reach within an hour?