The bridge contains many parallel segments. For example, look at the tower shown in the diagram. The tower contains two vertical, parallel segment as well as many transversals. One transversal is highlighted in the diagram.

1. Extend the highlighted transversal so that it continues beyond the parallel lines. (It has already been done in the picture above.)
2. Label the angles formed by the parallel lines and the transversal 1 — 8. Be sure angle 1 is an exterior angle.
3. What angles appears to be congruent to angle 1? What is the relationship of each angle to angle 1? Measure the angles to check your prediction.
4. What angles appear to be supplementary to angle 1? What is the relationship of each angle to angle 1? Measure the angle to check your prediction.
5. Choose an exterior angle that is not congruent to angle 1. What angles appear to be congruent to that angle? What is the relationship to each angle to this angle? Measure the angles to check your predictions.