The perimeter of a square is found by 4*side, which means the square paper has a perimeter of 4*20 = <<4*20=80>>80

Since the perimeter of the square is 20 cm shorter than the height of the computer screen, the height of the computer screen is 20+80 = <<20+80=100>>100cm.

# Answer

100
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
The perimeter of a square-shaped piece of paper is 20 cm shorter than the height of a computer screen. How many cm is the height of the screen if the side of the square paper is 20 cm?
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
100
The perimeter of a square-shaped piece of paper is 20 cm shorter than the height of a computer screen. How many cm is the height of the screen if the side of the square paper is 20 cm?
train