https://community.graphisoft.com/t5/Libraries-objects/basic-trigonometry-in-GDL-for-the-mathematically-challenged/m-p/20601#M38721 That did the trick!<BR /> Many thanks. Mon, 14 Feb 2005 12:44:43 GMT David Collins 2005-02-14T12:44:43Z https://community.graphisoft.com/t5/Libraries-objects/basic-trigonometry-in-GDL-for-the-mathematically-challenged/m-p/20599#M38719 <DIV class="actalk-migrated-content"><T>I'm trying to get GDL to come up with the adjacent angle of a right triangle for which I know the base and the hypotenuse. <BR /> SINa = Opposite/Hypotenuse. Cool.<BR /> How do I solve for "a"? All my old books assume I'm going to go look it up in the tables. Is there a way to get GDL to hand over the angle if I know the value of SINa?<BR /> I note with great interest that sin a = +/- SQR( 1-cos**a). Oh, my head!</T></DIV> Mon, 14 Feb 2005 08:03:48 GMT https://community.graphisoft.com/t5/Libraries-objects/basic-trigonometry-in-GDL-for-the-mathematically-challenged/m-p/20599#M38719 David Collins 2005-02-14T08:03:48Z https://community.graphisoft.com/t5/Libraries-objects/basic-trigonometry-in-GDL-for-the-mathematically-challenged/m-p/20600#M38720 Try the ASN fonction.<BR /> The syntaxe is <BR /> a = ASN (opposite/hypothenuse)<BR /> the value of "a" will be in this "area" : -90° &lt; ASN(x) &lt; 90° Mon, 14 Feb 2005 08:24:31 GMT https://community.graphisoft.com/t5/Libraries-objects/basic-trigonometry-in-GDL-for-the-mathematically-challenged/m-p/20600#M38720 Anonymous 2005-02-14T08:24:31Z https://community.graphisoft.com/t5/Libraries-objects/basic-trigonometry-in-GDL-for-the-mathematically-challenged/m-p/20601#M38721 That did the trick!<BR /> Many thanks. Mon, 14 Feb 2005 12:44:43 GMT https://community.graphisoft.com/t5/Libraries-objects/basic-trigonometry-in-GDL-for-the-mathematically-challenged/m-p/20601#M38721 David Collins 2005-02-14T12:44:43Z