Make Parallel Line

Make point D on the line. Make ray CD. This will be the transversal. Make point E to the right of D. Make point F on the transversal between D and C. Copy angle FDE to point C by selecting the angle copy tool and then selecting C then D then E and then F. This will create point G. Measure angles and C and D to see that they are congruent. Make the line though CG.