Get x,y along an arc with a defined starting & ending points I am trying to figure out how to create an arc and then get equidistant points along it. I've brought this here from Stack Overflow b/c it's more of a math question than a programming one, however I am not a math person so if you answer please keep in mind you're speaking to a layperson. 
I have a starting point:
(144,166)
I have an ending point:
(296,318)
My coordinate system starts at (0,0) on the upper left corner. 
I'd like to know how to get 4 equidistant points within an arc between my starting and ending points.

So how would I get the x,y for X1, X2, X3 & X4 ? 
 A: If the circle passes through
$A=(a, b)$ and $B=(c,d)$,
its center $C=(u, v)$ has to be
on the perpendicular bisector
of $AB$.
This line passes through
$D=(A+B)/2$
and,
since the slope of
$AB$ is
$m=\frac{d-b}{c-a}$,
 has slope
$-1/m = -\frac{c-a}{d-b}$.
The points on it
are of the form
$D-t(d-b, c-a)$
for real $t$.
Choose one of these,
and call it $P$.
Get the angles from
$P$ to $A$ and $P$ to $B$;
their difference is
$\angle APB$.
Now,
consider these points as complex numbers.
This allows rotation to be done
by multiplication.
Compute
$\theta = \angle APB/n$
($n=5$ in your case).
For $k$ from $1$ to $n-1$,
compute
$P+(P-A)(\cos(k\theta)+i\sin(k\theta)$,
which is the line from $P$ to $A$
rotated by
$k \theta$.
These are your points.
A: To make this easier we're going to use polar coordinates and a parametric representation. In polar coordinates, circles are defined by a center $(x_0,y_0)$, a radius $r$, and an angle $\theta$.
For your circle, $x_0$ is the x-value of the point $S$, and $y_0$ is the y-value of point $F$. Radius $r$ is equal to the difference in the x-value for $F$ and the x-value for $S$.
$x_0=144$, $y_0=318$, $r=152$
Then using a parametric representation of the circle in polar coordinates,
$x=144+152 cos(t)$, $y=318+152sin(t)$
Here, $t$ is a parametric parameter which can take any value, but of interest it represents $2 \pi$ radians of $\theta$. When you plug $t=0$ into the two parametric equations the $x$ and $y$ results will yield the point $F$, and $t=-\pi/2$ will yield the point $S$. Now just divide $t$ five times between $-\pi/2$ and $0$ for the five segments and find the $x$ and $y$ values that give you your arc points!
$-\pi/2+5a=0$, solving for $a$, $a=\pi/10$
So we have $t_{x1}=-\pi/2+\pi/10$, $t_{x2}=-\pi/2+2\pi/10$, etc. Finally, 
$X_1=(190.97,173.44)$, $X_2=(233.34,195.03)$, $X_3=(266.97,228.656)$, $X_4=(288.56,271.03)$
