Triangular Prism: The triangular prism refracts and partially reflects incident light. Place one or two triangular prisms anywhere in the simulation window. With Select depressed, you can move, resize, and rotate the triangular prism. You may place point light sources and beam projectors within the prism.

You can also change the width and height of the triangular prism using its Properties Box. In the Properties Box, you can also select the medium within the prism: air, water (default), glass, or diamond. The Properties Box lists the refractive index of each medium.