graphics with PSTric..

pose we want to draw a triangle with sides 2 cm, 3 cm and 4 cm as shownbelow:5cmC4cmMore on CoordinatesCoordinate gridsChanging sizeAnother type of coordinatesMore special coordinatesChanging the systemSetting parametersA6cmBWe can specify A as (0, 0) and B as (6, 0), but what about C? If ∠A = θ,then C has polar coordinates (5, θ). Now from elementary trigonometry, wehave√A = 2 tan −1 (s − b)(s − c)s(s − a)in any triangle ABC with BC = a, CA = b and AB = c, where s = 1 2 (a+b+c).For our triangle above, this works out to be√A = 2 tan −1 2.5 × 1.57.5 × 3.5This computation can be done by PostScript and in the syntax of this language,it is written2.5 1.5 mul sqrt 7.5 3.5 mul sqrt atan 2 mul(We will explain this a bit in the appendix to this chapter.) Now by thedevice of including PostScript code in an angle specification using !, we canproduce the above triangle byOnline L A T E X TutorialPart II – GraphicsPSTricksE Krishnan, CV Radhakrishnan and AJ Alexconstitute the graphics tutorial team.Comments and suggestions may be mailed totutorialteam@tug.org.inc○2002, 2003, The Indian T E X Users GroupThis document is generated by PDFT E X withhyperref, pstricks, pdftricks and pdfscreenpackages in an intel PC running GNU/LINUXand is released under LPPLThe Indian T E X Users GroupFloor iii, sjp Buildings, Cotton HillsTrivandrum 695014, indiahttp://www.tug.org.in£ ¡ ¢ ¤ ¥ ¦ © 13/23