A motorist pays for petrol at a filling station using a bank card for which a personal identification number must be entered on a keypad. There is a thick sheet of glass between the cashier and the motorist, with a gap at the bottom to give access to the keypad. When standing as shown in the diagram above, refraction of light through the glass means that the motorist is unable to see the keypad without moving his head to see under the glass. glass barrier key pad X The diagram above shows rays from the keypad. The light travelling initially along the path XA, which then passes through the glass, does not reach the motorist's eye. Assume no light passes through the surface AB. i. Add to the diagram to show that light travelling initially along the path XA does not reach the eye of the motorist. You will need to use a protractor to help you