dawson Posted March 10, 2013 Share Posted March 10, 2013 Not sure this is coffee shop talk, but wasn't sure where else to post it! This relates to me setting up my foreground in Stellarium. I'm not too hot on maths and can't get my head around this, and I thought there would be a geek or two here who might be able to work this out for me Can you tell me the angle at which both the orange line and the green line hits the red line in the illustration below. The orange line hits the red line at 3 feet above the ground, the green line hits the red line at 5 feet above the ground. Thanks for any replies. James Link to comment Share on other sites More sharing options...
T A WOW Posted March 10, 2013 Share Posted March 10, 2013 Need more information than that chief. What is the distance from (I'm assuming the wall) to the end of the where the two lines hit the floor? Link to comment Share on other sites More sharing options...
dawson Posted March 10, 2013 Author Share Posted March 10, 2013 I don't know where the line hits the floor, if I did even I could figure that one out well I could plug the numbers into an online calculator. I posed the same question on another forum I belong to and one bright spark has come up with the solution: "If x is the distance between the red line and the intersection of the yellow line with the baseline then3/x = 30/(23+x)which gives x = 23/9arctan (3/23/9) = arctan(27/23) = 49.57 degreesAnd the same for y (distance between the red line and the intersection of the green line with the baseline then)5/y = 30/(23 + y)y = 23/5arctan (5/23/5) = arctan (25/23) = 47.39 degrees" Link to comment Share on other sites More sharing options...
Tweedledee Posted March 10, 2013 Share Posted March 10, 2013 Red to orange line is... 180-90-arctan(27/23) = 40.426 degrees Red to green line is... 180-90-arctan(25/23) = 42.614 degrees Link to comment Share on other sites More sharing options...
dawson Posted March 10, 2013 Author Share Posted March 10, 2013 Sorry, I should have stipulated I wanted the angle to the right of the red line. James Link to comment Share on other sites More sharing options...
Tweedledee Posted March 10, 2013 Share Posted March 10, 2013 Your friend on the other forum gave the angles between the horizontal baseline and the coloured lines. I gave the angles between the red vertical line and the coloured lines. So you have both. Cheers, Pete. Link to comment Share on other sites More sharing options...
dawson Posted March 10, 2013 Author Share Posted March 10, 2013 Pete, thank you, I see. Yes, it s your answer I wanted. Thank you very much. Pat, what do you mean? James Link to comment Share on other sites More sharing options...
Tweedledee Posted March 10, 2013 Share Posted March 10, 2013 You're welcome James. I enjoy working these things out like some people do crossword puzzles (which I struggle with). I used to think I was pretty good at maths until my daughter got an A star in GCSE maths at just 15, a year ago in year 10, which is a year earlier than most of her school friends. She say's it's all my fault . Link to comment Share on other sites More sharing options...
dawson Posted March 10, 2013 Author Share Posted March 10, 2013 I don't get it either Pat Pete, I'm not even good at crosswords! James Link to comment Share on other sites More sharing options...
Tweedledee Posted March 10, 2013 Share Posted March 10, 2013 I don't get it either Pat Pete, I'm not even good at crosswords! James Well, you've done a fantastic job on your other thread explaining how to do custom foregrounds. That is really helpful, might have a go at that now, thanks James. Link to comment Share on other sites More sharing options...
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