# G-CO.12 Construction #5 Constructing Perpendicular Lines

## Geometric Constructions using a compass and a straightedge.

1. Draw line AB.
2. Put the compass point on A so that the compass measurement is over halfway to point B. Draw a long arc above and below the line.
3. Using the same compass measurement as step 2, place the compass on B and draw a long arc above and below the line so that it intersects the arc in step 2 at C and D.
4. Draw line CD.
5. Line AB line CD.