1. Draw two arcs with the same radius at point A and B.
2. Join the intersection points C and D (see picture). The line CD bisects arc AB into two equal parts.
3. The point S of intersection of arc AB and line CD is a middlepoint of the arc AB.
2. Join the intersection points C and D (see picture). The line CD bisects arc AB into two equal parts.
3. The point S of intersection of arc AB and line CD is a middlepoint of the arc AB.