Acryilic plastic, which can be used as a substitute for glass, is typically used as a building or craft material. In sheet form it can be cut with ordinary tools. These sheets have a protective covering made of paper and this should not be removed while cutting.
The score and break method can be used to cut acrylic up to 1/8 inch thick. Use a pencil to draw a cutting line on the paper, while using a strait edge. Use a sharp scoring tool to cut the line while applying downward pressure. This will snap the acrylic in two.
If the acryic plastic is thicker than 1/8 inch, use a power saw to get a smooth edge. Make sure to clamp most of the acryic plastic on a table to prevent it from moving around.