Problem :
Line AB is perpendicular to line CD.
Line EF is perpendicular to line CD. What is the
angle formed between line AB and line EF?
There is no angle formed: the lines are parallel.
Problem :
When perpendicular lines intersect, how many pairs of supplementary angles
are formed?
Six
Problem :
What is the shortest distance between two parallel lines?
A segment perpendicular to the parallel lines
with an endpoint on each line represents the
shortest distance between those lines.
