CK12 - Geometry

The planesthat are representedby the frontand side of the buildingaboveintersectat the corner. The

cornerappearsto be a right angle so the planesare perpendicular.

ParallelLine Postulate

As you alreadyknow, thereare manydifferentpostulatesand theoremsrelatingto geometry. It is important
for you to maintaina list of theseideasas they are presentedthroughoutthesechapters.One of the postulates
that involveslines and planesis calledtheParallelLine Postulate.

ParallelPostulate:Givena line and a pointnot on the line, thereis exactlyone line parallelto the given
line that goesthroughthat point.Lookat the followingdiagramto see this illustrated.

Line in the diagramaboveis near point. If you wantto drawa line that is parallelto that goes

throughpoint thereis only one option.Thinkof linesthat are parallelto as differentlatitude,like on

a map.Theycan be drawnanywhereaboveand belowline , but only one will travelthroughpoint.

Example 3

Drawa line throughpoint that is parallelto line.

Rememberthat thereare manydifferentlines that couldbe parallelto line.

Therecan only be one line parallelto that travelsthroughpoint. This line is drawnbelow.