Parallel Lines Cut by a Transversal

Parallel Lines Cut by a Transversal

by Michael Libron

​Linear Pair

​These angles formed a straight line. Thus, the sum of the two angles is 180 degrees.

​

​The non-common sides form a straight line. They are always adjacent angles, and are supplementary.

Poll

If linear pair is always supplementary, are all supplementary angles a linear pair?

• Yes

• Sometimes

• Never

Multiple Choice

What characteristic in a linear pair that may not be in supplementary angles?

• Two angles in a linear pair are always adjacent angles.

• Supplementary angles may or may not be an adjacent angles.

• Linear pair may composed of 3 angles that sums up to 180 degrees.

​Alternate-interior angles.

​These are angles in the opposite sides of the transversal and in between of the two other lines and are not linear pair.

Multiple Select

What are the pairs alternate-interior angles in the diagram?

• $$\angle APY\ and\ \angle XQD$$  

• $$\angle YPB\ and\ \angle CQX$$  

• $$\angle APY\ and\ \angle YPB$$  

​Alternate-exterior angles

Draw

Type the 2 pairs of alternate-exterior angles illustrated in the diagram.

​Vertical Angles

Multiple Select

Which of the following describes vertical angles illustrated in the diagram?

• $$\angle AEC\ and\ \angle DEB$$  

• $$\angle AED\ and\ \angle CEB$$  

• $$\angle AEC\ and\ \angle CEB$$