She moved beyond the boundaries of what was considered “acceptable” and conventional.
<h2>EXPLANATION:</h2>
Diane Arbus was an American picture taker noted for photos of minimized individuals—dwarfs, mammoths, transgender individuals, circus entertainers—and others whose ordinariness was seen by the general people as monstrous or strange. She moved past the limits of what was considered "adequate" and regular.
I'm guessing you mean in Photoshop so you would 1. click the ruler tool 2. drag it along the line you know is straight 3. on the options bar, click straighten