The height of an interior residential door is about 7 ft.
Doors on commercial buildings or upscale residences may be taller. The usual width is about 3 ft.
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My front door measures 6 2/3 ft high by about 3 ft wide. My bedroom doors are 2 1/2 ft wide. The minimum for ADA-compliant doors is 2 2/3 ft.
So we want to write a fraction that is less than 5/6 and has a denominator of 8. So lets start from 1/1 that is greater then 5/6 and doesn't have 8 as a denominator. Lets take one half from 1/1 and well get 1/2.
-2y=11-x
-7x+11-x=-13
-8x=-24
x=3
-2y=11-3
-2y=8
y=-4
15/7 is approximately 2.143