CK12 - Geometry

ConsecutiveInteriorAnglesTheoremIf two parallellines are crossedby a transversal,

then consecutiveinterioranglesare supplementary.

Proof:You will provethis as part of your exercises.

LessonSummary

In this lesson,we exploredhow to workwith differentanglescreatedby two parallellines and a transversal.
Specifically, we havelearned:

• How to identifyanglesformedby two parallellines and a non-perpendiculartransversal.


• How to identifyand use the CorrespondingAnglesPostulate.


• How to identifyand use the AlternateInteriorAnglesTheorem.


• How to identifyand use the AlternateExteriorAnglesTheorem.


• How to identifyand use the ConsecutiveInteriorAnglesTheorem.

Thesewill help you solvemanydifferenttypesof problems.Alwaysbe on the lookoutfor new and interesting
waysto analyzelines and anglesin mathematicalsituations.

PointsTo Consider

You usedlogic to workthrougha numberof differentscenariosin this lesson.Alwaysapplylogic to mathe-
maticalsituationsto makesure that they are reasonable.Evenif it doesn’thelp you solvethe problem,it
will help you noticecarelesserrorsor othermistakes.

LessonExercises

Solveeachproblem.

Use the diagrambelowfor Questions1-4. In the diagram,lines and are parallel.

1. Whatterm best describesthe relationshipbetween and

a. alternateexteriorangles

b. consecutiveinteriorangles

c. correspondingangles

d. alternateinteriorangles

2. Whatterm best describesthe mathematicalrelationshipbetween and?