Python turtle program not drawing polygon properly - python-3.x

Question

When I run the program using the turtle tool, it just makes one horizontal line and does not make a complete shape. I am not sure why this is happening. I have already made a working program that would draw a predetermined shape such as a square. I have already tested my computations and I believe my for-loop is correct. Am I making just some silly syntax error?
# polygon program
# get inputs
side_count = int(input( "How many sides does the polygon have?" ))
side_length = int(input( "How long is each side?" ))
# compute side angle
shape_angle = (side_count - 2) * 180
# import turtle modules
from turtle import *
# measure angles in
degrees()
# drawing speed
speed( 6 )
# square specs
color( 'green' )
width( 3 )
setheading( 0 )
# forloop to draw the polygon
for side in range ( side_count ):
forward ( side_length )
left ( shape_angle )
# all done drawing
done()

Answer 1

Although I agree with #TudorPopescu that this line is your primary issue:
shape_angle = (side_count - 2) * 180
That solution doesn't work for me, so I suggest something simpler to start:
shape_angle = 360 / side_count
Your code reworked with the above fix and style changes:
# polygon program
# import turtle modules
from turtle import *
# get inputs
side_count = int(input("How many sides does the polygon have? "))
side_length = int(input("How long is each side? "))
# compute side angle
shape_angle = 360 / side_count
# measure angles in
degrees() # the default
# drawing speed
speed('normal') # the default
# square specs
color('green')
width(3)
setheading(0) # the default initial heading
# for loop to draw the polygon
for side in range(side_count):
forward(side_length)
left(shape_angle)
# all done drawing
done()

Answer 2

First of all, import all your modules first, its not necessary until you have to use it, but it's a good habit. Also the shape_angle is the total of the whole shape.
To make it work you would have your original code:
shape_angle = (side_count - 2) * 180
Then put it in brackets and divide it by side_count to find the individual angle, the result:
shape_angle = ((side_count - 2) * 180) / side_count
Also get rid of the degrees
import turtle as *
side_count = int(input( "How many sides does the polygon have?" ))
side_length = int(input( "How long is each side?" ))
shape_angle = ((side_count - 2) * 180) / side_count
speed( 6 )
color( 'green' )
width( 3 )
setheading( 0 )
for side in range ( side_count ):
forward ( side_length )
left ( shape_angle )
done()
`