Member Avatar for Elizabeth_13

I am stuck trying to figure this out. I need to find the slope of a line after the user is prompted to click two points and display the line. I know to find slope you need y2 - y1/x2 - x1 but how can I do that if there are only two points to a line?

from graphics import*

def main():

win = GraphWin("Calculates Slope", 400, 400)
win.setCoords(-100, -100, 100, 100)
win.setBackground("white")

c = Circle(Point(0,0),2)
c.draw(win)
c.setFill("black")

centerPoint = Text(Point(11,8), "(0,0)")
centerPoint.draw(win)

xLine = Line(Point(100,0), Point(-100,0)) 
xLine.draw(win)

yLine = Line(Point(0,-100), Point(0,100))
yLine.draw(win)

for i in range(20):
    tickMark = Text(Point(-10*i,0), "|")
    tickMark.draw(win)

    tickMark = Text(Point(10*i,0), "|")
    tickMark.draw(win)        

for i in range(20):     #start stop step
    tickMark2 = Text(Point(0,-10*i,),"__")  # -10 goes down Y 
    tickMark2.draw(win) # -10*i gives more space

    tickMark2 = Text(Point(0,10*i,),"__")  # 10 goes up Y 
    tickMark2.draw(win)    

point = Text(Point(10,80), "Please click to create the first point")   
point.draw(win)

x1 = win.getMouse()
x1.draw(win)

x2 = win.getMouse()
x2.draw(win)

slope = Text(Point(10,70), "The slope of the line is: ")
slope.draw(win)

main()

Edited by JamesCherrill because: Moved to correct forum (Programming/software development)
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  • Latest Post Latest Post by Reverend Jim
Member Avatar for Reverend Jim

Without getting into the code, if you have two points then you have the coordinates (x,y) of both points, therefore you can calculate (y2 - y1)/(x2 - x1). Note the importance of parentheses.

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