I have two plots I1 and I2 for two different lines perpendicular to each other. When I combine these graphs they do not perpendicular to each other.
I1 = Plot[{-4 (x - 1) + 13}, {x, -1, 3}];
I2 = Plot[{(x - 1)/4 + 13}, {x, -1, 3}];
Show[I1,I2]
In your case you'll want a square grid:
I1 = Plot[{-4 (x - 1) + 13}, {x, -1, 3}, AspectRatio -> Automatic]
I2 = Plot[{(x - 1)/4 + 13}, {x, -1, 3}]
Show[I1, I2]
Plot[{-4 (x - 1) + 13, (x - 1)/4 + 13}, {x, -1, 3}, AspectRatio -> Automatic]
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