Handbook
- Tutorial
- Problems about orthogonality and parallelism
Draw the parallel to a line from a point
external to it
Line1 is the given line and C is the point external to it.
Build the line Line1, using Line, and the point
C, using Point.
Build a circle Circle1, centered in a point A of Line1, using
Circle with center point, with radius AC.
This circle intersects Line1 in a point D.
Build two other circles, Circle2 and Circle3, centered in C and in E, respectively, with the same radius, using
Circle with center point.
These two circles intersect in a point F.
Build another line, using Line, joining
C with F.
This is the desired parallel, infact, the quadrilateral ACFE is a rhomb because it has four equal sides by construction. So, the opposite sides CF and AE are parallel.
Build a circle Circle1, centered in a point A of Line1, using
Build two other circles, Circle2 and Circle3, centered in C and in E, respectively, with the same radius, using
Build another line, using 
