Line perpendicular to a Point on a Line
Step 1:Using a ruler or a straight edge, draw line segment AB
Step 2: Using your compass tool, draw a circle with the center being point A that has a radius that is larger than half the length of line AB ( don't change your compass)
Step 3: Now use that same compass measure, and make another circle with the center being point B
Step 4: Where the two circles intersect, name those two points C and D
Step 5: Using a ruler or line segment tool, draw a line from point C to point D
Step 6: Where line AB and line CD meet, name that point E
That line intersection at point E is a perfect 90 degree angle