Samsung SP-L331 - Manual (Page 17)

Installation and Connection 2-6
12. Adjust the projector's angle so that a corner of the projected picture (which is nearest to the projector) meets that of the
screen. In the illustration below, this corner is labeled D.
A : Projector / B : Screen / C : Projected image / D : A corner of the picture nearest to the projector
13. Adjust the projector's angle until the projected image covers the entire screen area. The image can overlap.
The projected image may not cover the entire screen depending on the projector's installation height. In this case, adjust
the projector's angle so that the entire screen is covered.