Draw an arc from C as a center, using any
convenient radius cutting AC and CB at X
Increase the size of the radius and from X
and Y, draw arcs which intersect at point F.
Draw CF which is perpendicular to AB at
3. Using a compass, from a point outside the line.
Draw a perpendicular to AB from C.
From C, draw an arc using any convenient
radius, intersecting AB at X and Y.
Using the same radius, draw arcs from X
and Y intersecting at F.
Draw CF, which is perpendicular to AB.
4. Using a compass from a point at the end of a line.
Draw a perpendicular to AB from B.
From B, swing an arc with any convenient
radius intersecting AB at O and continuing
in a clockwise direction at least 120°.
From O, using the same radius, draw an arc
intersecting the arc drawn in Step 1 and X.
From point X, draw an arc with the same
radius intersecting the arc drawn in Step 1
From X and Y, draw arcs using the same
radius intersecting at F,
Draw FB perpendicular to AB at B.
Two lines are said to be parallel if they are equidis-
tant (equally distant) at all points.
Facts about parallel lines:
Two straight lines lying in the same plane either
intersect or are parallel.
Through a point there can be only one parallel
drawn to a given line.
If two lines are perpendicular to the third, and in the
same plane, they are parallel.
It is often necessary to find the midpoint of a line.
This may be found by measuring, or by using dividers
and finding it by trial and error. A much simpler way is
by the use of a compass.
To bisect a line AB by using a compass: