Construction #6
Perpendicular to a line and through a point not on the line
To see a video of Mr. Ochs doing examples
Mr Ochs Video To see and example done in flash click on a link below Math Open Ref Math is Fun |
|
Given a line and a point not on the line, construct the perpendicular to the line through the given point.
Construct the perpendicular bisector of line l at point A.
1) Choose a radius for the compass that is greater than the distance from the point to the line.
2) With this radius, place the pointer on point A and strike 2 arcs that intersect line l to form a new segment XY on line l.
(at this point you are going to do construction #4 to bisect the segment XY and draw the perpendicular that will pass through point A, which is on the perpendicular bisector of segment XY)
1) Choose a radius for the compass that is larger than ½ the segment.
2) With this radius place your compass pointer on one endpoint of the segment and strike a semicircle(1/2 circle) that passes through the segment.
3) Keeping the same radius, repeat step 2 with the pointer on the other endpoint of the segment. The two semicircles will intersect.
4) With a straight edge draw a line through the points of intersection created by the arcs in steps 2 and 3.
Construct the perpendicular bisector of line l at point A.
1) Choose a radius for the compass that is greater than the distance from the point to the line.
2) With this radius, place the pointer on point A and strike 2 arcs that intersect line l to form a new segment XY on line l.
(at this point you are going to do construction #4 to bisect the segment XY and draw the perpendicular that will pass through point A, which is on the perpendicular bisector of segment XY)
1) Choose a radius for the compass that is larger than ½ the segment.
2) With this radius place your compass pointer on one endpoint of the segment and strike a semicircle(1/2 circle) that passes through the segment.
3) Keeping the same radius, repeat step 2 with the pointer on the other endpoint of the segment. The two semicircles will intersect.
4) With a straight edge draw a line through the points of intersection created by the arcs in steps 2 and 3.