Secondary school, but it's still in the revision guide so I assume they still teach it. https://www.bbc.co.uk/bitesize/guides/z6r37nb/revision/6 https://www.bb

Secondary school, but it's still in the revision guide so I assume they still teach it. https://www.bbc.co.uk/bitesize/guides/z6r37nb/revision/6 https://www.bbc.co.uk/bitesize/guides/z6r37nb/revision/6