This multi-sized ruler features two triangles in one.

Use the 45-degree side to cut half-square triangles from strips up to 5-1/2 inches wide, creating half-square triangles up to a finished size of 5 inches.

Use the 90-degree side to cut quarter triangles that finish up to a 5-inch quarter-square triangle. The math required to cut these angles is incorporated into the easy-to-read black-and-white markings.