CK12 - Geometry

Whichof the figuresbelowshows

Rememberthat a ray has one endpointand extendsinfinitelyin one direction.ChoiceA is a line segment
sinceit has two endpoints.ChoiceB has one endpointand extendsinfinitelyin one direction,so it is a ray.
ChoiceC has no endpointsand extendsinfinitelyin two directions—itis a line. ChoiceD also showsa ray

with endpoint Sincewe needto identify with endpoint , we knowthat choiceB is correct.

Example 2

Use this spaceto draw.

Rememberthat you are not expectedto be an artist.In geometry, you simplyneedto drawfiguresthat
accuratelyrepresentthe termsin question.This problemasks you to drawa ray. Beginwith a line segment.
Use your ruler to drawa straightline segmentof any length.

Now drawan endpointon one end and an arrowon the other.

Finally, labelthe endpoint and anotherpointon the ray.

The diagramaboveshows.

Angles

Anangleis formedwhentwo rays sharea commonendpoint. That commonendpointis calledthevertex

and the two rays are calledthesidesof the angle.In the diagrambelow, and form an angle,

, or for short.The symbol is usedfor namingangles.

The samebasicdefinitionfor anglealso holdswhenlines,segments,or rays intersect.