# Language of Geometry

lunifer's version from 2017-01-20 01:31

## NOTE

To change the blank section, look at the bottom of it and click "switch column".

## Chart of Lines

TermSymbolLooks LikeDescription
PointsIdentify a position. Represented by dots.
LinesLines are made up of a set of points. A line goes on forever in both directions.
RaysA____B_> (missing image)A ray is a part of a line with one endpoint.
Line SegmentA___B (missing image)A line segment is part of a line with two end points.
Angle< ABC or < CBAFormed by ray or line segments with a common endpoint. Endpoint is the vertex.

## Other Lines

ParallelParallel Lines are two lines that never intersect.
IntersectingIntersecting Lines are lines that cross each other at exactly one point, called the point of intersection.
PerpendicularPerpendicular Lines are two lines that form a right angle at their point of intersection.

## Chart of Angles

ClassificationAngle MeasuresDiagramAngle Names
AcuteLess than 90 degrees< ABC = 30 degrees OR < CBA = 30 degrees
Rightis 90 degrees< DEF = 90 degrees OR < FED = 90 degrees
ObtuseBetween 90 and 180 degrees< GHI = 125 degrees OR IHG = 125 degrees
StraightIs 180 degreesJ.____K.___L. (missing image)< JKL = 180 degrees OR < LKJ = 180 degrees
ReflexBetween 180 and 360 degrees< MNO = 330 degrees OR < ONM = 330 degrees
ComplementaryAngles that up to 90 degrees.< ABD + < DBC = 90 degrees (example)
SupplementaryAngles that up to 180 degrees.< ABD + < DBC = 180 degrees(example)