Stick some cubes together to make a cuboid. Find two of the angles
by as many different methods as you can devise.
A box of size $a$ cm by $b$ cm by $c$ cm is to be wrapped with a
square shaped piece of wrapping paper. Cutting the paper is not
allowed so what is the smallest square this sheet can be?
Now suppose we want to wrap up a cube, what is the smallest
square of wrapping paper that can be used to minimise wastage?