Postby rob » Yesterday, 21:49
You were using radians when you have to use degrees. Not sure how to set degrees in Excel, though.
Gentlemen, this is again proof of me not understanding mathematics. In my simple mind I had envisioned a half circle which will be 180 degrees. Never heard of radian.dpc wrote:Use the Excel function RADIANS to convert a value in degrees to radians.
sine of BC (30 deg) should be 0.5.
cosine of BC should be 0.8660254
Looking to the following websites
http://en.wikipedia.org/wiki/Radian
http://en.wikipedia.org/wiki/Degree_%28angle%29
http://math.rice.edu/~pcmi/sphere/drg_txt.html
http://www.mathsisfun.com/geometry/radians.html
http://www.teacherschoice.com.au/maths_ ... angles.htm
A radian is the length from the middle of the circle towards the outer edge which, in mathematics, has the sign of r.
However this is also the unknown length of b.
It is then used to calculate the total lenght of the circle.
Lets give it a try
degree = radians *(180/phi)
30 = radians * (180/1.61803399)
30 / 111,2461179 = radians
0,269672332 = radians
Nah, I can't imagine that the length of b is so short when c is over 30
I don't think radian is something that I need to be concerned about. Because radian has something to do with the radius of a circle. And we are not trying to calculate the radius of a circle. We try to calculate a triangle which has unequal legs a and b in which c is known and the corners of each intersection point.
Lets have a look at the wiki for triangles
http://en.wikipedia.org/wiki/Triangle#C ... and_angles
Usefull information but I don't know how to transfer them into that one meaningfull calculation.
But firt I go to sleep