Example 2

When building the stairway railing, a carpenter will cut the top and bottom of each spindle end at the same angle.

  1. What can you conclude about the spindles?

    The top and bottom of each spindle was cut at the same angle, which is represented in the diagram below. The measures of each pair of corresponding angles for the spindles are equal so the spindles must be parallel.


  2. What can you conclude about the upper and lower rails?

    Similarly, the alternate interior angles for the upper and lower rails are equal so the upper and lower rails must be parallel.