G-CO.12 Construction #6 Perpendicular bisector of a line segment
Geometric Construction using a compass and straightedge.
1. Draw line segment AB.
2. Put the compass point on A so that the compass measures longer than over halfway to B and draw a long arc above and below segment AB.
3. Using the same compass measurement as step 2, place the compass on point B and draw a long arc above and below so that it intersects the arc from step 2 at C and D.
4. Draw line CD.
5. The intersection of line segment AB and line CD is point M.
6. M is the midpoint of segment AB. Line CD is the perpendicular bisector of segment AB. AMC is a right angle.