Symbols in Geometry

Common Symbols Used in Geometry

Symbols save time and space when writing. Here are the most common geometrical symbols:

Symbol	Meaning	Example	In Words
	Triangle	ABC has 3 equal sides	Triangle ABC has three equal sides
	Angle	ABC is 45°	The angle formed by ABC is 45 degrees.
	Perpendicular	ABCD	The line AB is perpendicular to line CD
	Parallel	EFGH	The line EF is parallel to line GH
	Degrees	360° makes a full circle
	Right Angle (90°)	is 90°	A right angle is 90 degrees
	Line Segment "AB"	AB	The line between A and B
	Line "AB"		The infinite line that includes A and B
	Ray "AB"		The line that starts at A, goes through B and continues on
	Congruent (same shape and size)	ABC DEF	Triangle ABC is congruent to triangle DEF
	Similar (same shape, different size)	DEFMNO	Triangle DEF is similar to triangle MNO
	Therefore	a=b b=a	a equals b, therefore b equals a

Naming Angles

Short Example

	So now, when someone writes:	In ABC, BAC is
	You know they are saying:	"In triangle ABC, the angle BAC is a right angle"