The orientation of the graph does not match the coordinates.
Assuming that the coordinates are correct --
Since B = (8,-2) and C = (8,6) ---> E = (8,2)
The equation of ES: y = 2
Since A = (2,-3) and B = (8,-2) ---> C = (5,-2.5)
slope of AB = [-2 -(-3)] / [8 - (2)] = 1/6
Since the slope of AB = 1/6 ---> the slope of DS = -6
The equation of DS: y - (-2.5) = -6(x - 5)
y + 2.5 = -6x + 30
y = -6x + 27.5
Since y = 2 ---> 2 = -6x + 27.5
6x = 25.5
x = 4.25
Therefore, the coordinates of S are (4.25, 2)
The distance from S to E will be the circumference;
the distance from (4.25,2) to (8.2) is 3.75