To draw accurately by the work of a single person when arcs or a square triangle is drawn by using a measure at a construction site or the like.

A graduation line 4 extending linearly in the longitudinal direction is provided on the center in the width direction of a rectangular body of a measure 1, and the value of square root such as '√2m' is shown together with the graduation numerical value such as '1m' is also shown on the graduation line 4. Small perforations 5 are perforated on the position of 0 and an optional numerical value, and a supporting point pen is inserted onto the 0 position and arcs of radius of 1m √ 2m or the like can be drawn by using the supporting point pen as the supporting point. A square triangle can also be drawn.