Funny this would come up now. I've been helping my son with his homework and it just happened to be about graphing linear equations. Remember, slope is expressed as the ratio of rise over run. Of course a ratio can also be expressed as a percentage, so a 100 percent slope has a rise equal to its run, or a ratio of 1:1. That yields a 45 degree angle, not a 90 degree angle, just as Deloy reminded us. A 20 percent slope gives an angle of 11.31 degrees. Chuck can be forgiven. He has more important things on his mind. I'm just bored and found a moment to respond. Kim -----Original Message----- From: utah-astronomy-bounces@mailman.xmission.com [mailto:utah-astronomy-bounces@mailman.xmission.com] On Behalf Of M Wilson Sent: Wednesday, August 29, 2012 9:44 PM To: Utah Astronomy Subject: Re: [Utah-astronomy] 20% Grade? Wrong, go to http://en.wikipedia.org/wiki/File:Grades_degrees.svg as suggested by Chrismo ________________________________ From: Chuck Hards <chuck.hards@gmail.com> To: Utah Astronomy <utah-astronomy@mailman.xmission.com> Sent: Wednesday, August 29, 2012 6:54 PM Subject: Re: [Utah-astronomy] 20% Grade? You dont even need a protractor. Just calculate 20% of 90. Go to public grade school in Utah, did you? On Aug 29, 2012 3:30 PM, "D P Pierce" <starsbirdsglyphs@gmail.com> wrote:
Seth, About what degree angle would 20% be? I think I remember a 20% grade means that in a 100 feet of horizontal travel the grade increases or decreases 20 feet. That would mean a 100% grade would be a 45 degree angle. I think a 20% grade would be a lot less than a 20 degree angle. I've forgotten all of my trigonometry or I could calculate it myself.
Deloy