Symbols in Geometry
Common Symbols Used in Geometry
Symbols save time and space when writing. Here are the most common geometrical symbols:
|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|
When someone writes: In ABC, BAC is
They are really saying: "In triangle ABC, the angle BAC is a right angle"
For angles the central letter is where the angle is.
when we write "ABC is 45°", the point "B" is where the angle is.