Please help me answer this Physics problem!?

Please help me answer this Physics problem!?

A pinhole camera consists of a cube with a hole in one face and pane of dark glass making the opposite face. This pinhole camera is used to take a picture of a person of height 1.8m standing 6m away from the camera. The depth of the camera, from hole to screen, is 40cm. Find the height of the image of the person.