How to calculate position on a circle with a certain angle?

Question

I\'m trying to figure out how I could be able to calculate coordinates on a circle. For simplicity I made some images.

Answer 1

This need some mathematics here. You need to know if two lines are perpendicular to each other, The multiplication of those two lines gradient should equals to -1.

Then

m1=(770-500)/(540-400)=27/14

same way

m2=(y-770)/(x-540)

(x,y) is the point you want to find.

Now

m1*m2=-1

Now we got one equation. You need another since there are two variable needs to find

You can get another by considering the radius of the circle.

r=sqrt((540-400)^2+(770-500)^2)

Same way

r=sqrl((x-540)^2+(y-770)^2)

Now you got two equation and only needs to solve. This will give you two set of coordinates. Since there can be -90 and 90 degrees.