Copy of Naming Angle Positions
Definition: A transversal is a line that intersects 2 other lines at 2 distinct points.
In the applet, the dashed line below is a transversal. (Actually, each of the three lines displayed below is a transversal.)
When a transversal intersects 2 other lines, special names are given to certain pairs of angles.
These angle pairs are called corresponding angles, alternate interior angles, alternate exterior angles, same-side interior angles, and same-side exterior angles.
Explore these angle pairs within the applet below. Then, answer the questions that follow.
Questions:
1) What does the term "same-side" mean in the phrases "same-side interior angles" and "same-side exterior angles"?
It means the the angles lay on the same side of the transversal yet it lies inside the two lines.
2) What does the term "alternate" mean in the phrases "alternate interior angles" and "alternate exterior angles"?
It means that the angles inside the area between the two lines are on alternate sides of the transversal.
3) Which of the four displayed angles would be considered "interior" angles? Why is this?
The interior angles would be the ones the are between the top line and the bottom line and it doesn't matter which side of the transversal it is at.
4) Which of the four displayed angles would be considered "exterior" angles? Why is this?
The exterior angle are the ones on the top of the top line or bottom of the bottom line and this is because the angles are on the outside of the area between the two lines.
5) How would you describe, in your own words, what it means for a pair of angles to be described as "corresponding angles"?
Corresponding angles are those that share a transversal and are on the same side of the transversal and one angle in on the inside and the other is on the exterior.