Undefined Terms in Geometry

Basic Terms of Geometry

by Heather Belcik

​Undefined Terms

​Point- a location in space. It has no size or shape.

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​Named by a capital Letter.

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​Point M; Point R

​Point T; Point N

​Point P; Point Q

Line- a straight path that extends in two opposite directions without end and has no thickness. It contains infinitely points.

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​Named by 2 capital letters or a lowercase script letter.

​line g;   line PN;      line PT;    line TN

​line h;   line RT;      line RQ;    line TQ

​line j;   line MT;     

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​symbol 

​Plane- a flat surface that extends without end and has no thickness.  Contains infinitely many lines.

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​Named by a capital Script letter.

​​Plane S

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​Named by 3 noncollinear points.

​Plane PTQ;  Plane RTN

​Plane PTR;  Plane QTN

​Points

​Name all the points in the diagram.

​Points

​Name all the points in the diagram.

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Point V

​Point W

​Point X

​Point Y

​Point Z

​Point T

​Lines

​Name all the lines in the diagram.

​Lines

​Name all the lines in the diagram.

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line n; Line VW; Line WX; Line XY

​ Line VX; Line VY; Line WY

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​line r; Line TX

​Planes

​Name the plane in two ways.

​Planes

​Name the plane in two ways.

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​Plane P

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​Plane VWZ; Plane VXZ;

​Plane VYZ: Plane WXZ;

​Plane WYZ; Plane XYZ