TA triangular shaped object can be suspended from any corner by a nail at the top of the support. The center of mass will be directly below each corner, as defined by the plumb bob. Lines of the vertical position of the bob’s string is drawn on the object. The intersection of all the lines is the position of the center of mass.
See also demonstration B1-01: CENTER OF MASS - DISC SECTION. These two demonstrations use the same stand and are often taught together.
Ask students: What would happen if the triangle was suspended at its center of mass?