When a transversal intersects two lines, the two lines are parallel if and only if interior angles on the same side of the transversal and exterior angles on the same side of the transversal are supplementary (sum to 180°).
Q. How do you find vertical angles examples?
Example: Find angles a°, b° and c° below: Angles a° and c° are also vertical angles, so must be equal, which means they are 140° each. Answer: a = 140°, b = 40° and c = 140°. Note: They are also called Vertically Opposite Angles, which is just a more exact way of saying the same thing.
Q. What does alternate interior angles look like?
Alternate Interior Angles are a pair of angles on the inner side of each of those two lines but on opposite sides of the transversal.
Q. What is another name for same side interior angles?
The pairs of angles on one side of the transversal but inside the two lines are called Consecutive Interior Angles.
Q. Does it make sense that same side interior angles are supplementary?
Same side interior angles are always supplementary, meaning that the sum of their measures if 180°. So, if one of the same side angles is unknown and written as an expression with a variable, and the other same side angle is give, set their sum equal to 180°.
Q. What is the difference between corresponding angles and same side interior angles?
The angles are on the SAME SIDE of the transversal, one INTERIOR and one EXTERIOR, but not adjacent. The angles lie on the same side of the transversal in “corresponding” positions. If two parallel lines are cut by a transversal, the corresponding angles are congruent.
Q. Are same side interior angles adjacent?
The same side interior angles are non-adjacent and lie on the same side of the transversal. Two lines are parallel if and only if the same side interior angles are supplementary.
Q. Why are same side interior angles sometimes congruent?
Same side interior angles are sometimes congruent. Rather, they are supplementary (i.e., add up to $$180º ), so they are only congruent when they are both $$90º .
Q. What happens if the lines aren’t parallel which angle types are still congruent?
The answer for the question is the first option, which is: Vertical. By definition, the vertical angles are those opposite angles that are formed by intersecting lines. Keeping this on mind, if the red lines shown in the figure above are not parallel, the vertical angles of each one them are still congruent.
