you've forgotten tooit' degrees around the whole circle ( if you plot points on circleeach is degrees from the lastor / python' standard math module gives all the required constants and functions from that point forward--pisineand cosine the math is really not too obscure if you study this long enough (in conjunction with your old geometry text if necessarythere are alternative ways to code the number crunchingbut 'll skip the details here (see the examples package for hintseven if you don' care about the maththoughcheck out example - ' circle function given the ( ,ycoordinates of point on the circle returned by pointit draws line from the circle' center out to the point and small rectangle around the point itself--not unlike the hands and points of an analog clock canvas tags are used to associate drawn objects for deletion before each plot example - pp \gui\clock\plottergui py plot circles on canvas import mathsys from tkinter import def point(tickrangeradius)angle tick ( rangeradiansperdegree math pi pointx introundradius math sin(angle radiansperdegree)pointy introundradius math cos(angle radiansperdegree)return (pointxpointydef circle(pointsradiuscenterxcenteryslow= )canvas delete('lines'canvas delete('points'for in range(points)xy point( + pointsradius- scaledxscaledy ( centerx)(centery ycanvas create_line(centerxcenteryscaledxscaledytag='lines'canvas create_rectangle(scaledx- scaledy- scaledx+ scaledy+ fill='red'tag='points'if slowcanvas update(def plotter() /trunc div circle(scalevar get()(width / )originxoriginycheckvar get()def makewidgets()global canvasscalevarcheckvar canvas canvas(width=widthheight=widthcanvas pack(side=topscalevar intvar(checkvar intvar(scale scale(label='points on circle'variable=scalevarfrom_= to= scale pack(side=leftcheckbutton(text='slow mode'variable=checkvarpack(side=leftbutton(text='plot'command=plotterpack(side=leftpadx= complete gui programs