54. A movie projector emits light as shown in the top-view diagram below. To make the light projection cover the full width of a 12-foot screen without extending beyond the screen, the projector must be placed a certain distance from the screen. Assuming the screen is positioned directly in front of the projector as shown, which of the following expressions could be used to calculate the distance, in feet, from the projector to the screen?

F.

G.