# Defining a circle using Polynomial Method:

The first method defines a circle with the second-order polynomial equation as shown in fig:

y2=r2-x2
Where x = the x coordinate
y = the y coordinate

With the method, each x coordinate in the sector, from 90° to 45°, is found by stepping x from 0 to & each y coordinate is found by evaluating for each step of x. ## Algorithm:

Step1: Set the initial variables
(h, k) = coordinates of circle center
x=o
I = step size
xend= Step2: Test to determine whether the entire circle has been scan-converted.

If x > xend then stop.

Step3: Compute y = Step4: Plot the eight points found by symmetry concerning the center (h, k) at the current (x, y) coordinates.

Plot (x + h, y +k)          Plot (-x + h, -y + k)
Plot (y + h, x + k)          Plot (-y + h, -x + k)
Plot (-y + h, x + k)          Plot (y + h, -x + k)
Plot (-x + h, y + k)          Plot (x + h, -y + k)

Step5: Increment x = x + i

Step6: Go to step (ii).

### Program to draw a circle using Polynomial Method:

Output:    