When dealing with 2 dimensional shapes, the 2 most important values we need to be able to calculate are the area and perimeter of the shape. With 3 dimensional shapes the 2 most important values are the volume and the surface area.
By this stage in our mathematical journey, we should have permanently memorised the formulae that allow us to calculate these values. Without the formulae permanently memorised, we will not be able to tackle complicated questions involving these shapes. So if you have avoided memorising them during previous years, now is the time to sit down and make sure you have the formulae memorised for each of these basic shapes.