Hey Shaw,
Thanks heaps for your reply. I think you may have answered my next question. But I don't think I was very clear with my question in the first place which has probably led to misunderstanding ( i did post it at 4am aussie time last night
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You said:
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Given an ellipse and a point on the ellipse (red dot below), place a triangle of height one and base one which is normal to the point with the additional stipulation that the legs of the triangle then be extended down to the arc of the ellipse. Then rotate such figure through an angle .
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now that is an interesting question, and may in fact be very useful to what I want to do. But so far i haven't got as far as
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given... a point on the ellipse
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. Which is what I was trying to get to in my original post.
So here's another way of asking it, actually sorry, its a bit of a different question, but it just came to me.
I have an ellipse. I draw a cross hair in this to form 4 right angled triangles. I know their dimensions because I know the width/height of the ellipse. What I want to know is if you take a line out from the right angle of the top right triangle and extend it out, forming an acute angle, when will it hit the perimeter of the ellipse? What will the x,y co-ordinates of this intersection point be assuming that the centre point of the ellipse is 0,0.
because I'm drawing a figure using code, i need a way for the code to know where to start drawing a line so that it intercepts the head (ellipse).