A template is a formed piece of metal, wood, card, plastic, or other medium used as a guide for processes such as painting, cutting out shaping and drilling. It is a mold or pattern used as a single guide to make, design or construct items.
A compass is an instrument used for drafting so that exact circles may be drawn by using the pinpoint side to point the center and adjust the other side which holds a pencil to draw the circle by drawing around the center point. A ruler is a device with equally spaced markings along its length. It can also be used in technical drawing.