Can you work out the dimensions of the three cubes?
What is the volume of the solid formed by rotating this right
angled triangle about the hypotenuse?
Imagine two identical cylindrical pipes meeting at right angles and think about the shape of the space which belongs to both pipes. Early Chinese mathematicians call this shape the mouhefanggai.
You might like to imagine cutting the mound of earth into a
cuboid, four prisms and four little pyramids in the corners. You'll
need the formula (Area of base x Height)/3 for the volume of a