how do you work out the total surface area of a hemisphere?
['Diameter of a hemisphere: d = 2 * r ,', 'Volume of a hemisphere: V = 2/3 * π * r³ ,', 'Base surface area of a hemisphere: Ab = π * r² ,', 'Cap surface area of a hemisphere: Ac = 2 * π * r² ,', 'Total surface area of a hemisphere: A = 3 * π * r² ,']