Construct a Perpendicular Line through a point Not on the line
Follow these steps to construct a perpendicular line through a point not on the line
1) Using the POINT TOOL, mark point D on segment AB.
2) Using the COMPASS TOOL, create a circle with radius CD and center C.
3) Using the POINT TOOL, mark point F at the intersection of circle C and segment AB.
Next we will create the perpendicular bisector of segment DF. Follow the steps to create below if you don't remember how to construct it.
4) Using the COMPASS TOOL, create a circle with radius FD and center F.
5) Using the COMPASS TOOL, create a circle with radius FD and center D.
6) Using the LINE TOOL, draw a line that passes through C and the intersections of circles F and D.