 So you just want to be aligned, not a problem. Edge Align allows you to make a clean cut from one edge to another. If you left click this edge and left click on this one, you'll see it flattens everything in between. If you ever need to reset the first point, just press space bar as usual. Normally you would use this on the edges that are closest to the corner, but you can technically do it from farther away. Just keep in mind that the walls might not follow the edges. While left click drag and you can expand the alignment outwards and the shape of the expansion is determined by the buttons here and the direction of the expansion is controlled under the modifiers here. For now, let's just worry about the shape. The easiest one to understand is the straight line. If we click and drag it out, you can see that it tries to expand in the shape of a straight line as opposed to a circle which expands in a much rounder shape. In order, here is what they all look like. Bezier curve, arcs, small round corners, spline, arcs and line, tight round corners, circle, round corners and straight lines. Now, at the bottom, you get to change the direction the expansion happens. So, just for reference, this is what it looks like by normal default. Usually, you can just left click drag to control the expansion, but if you would rather it automatically snap to a specific amount, you can set that here. Now, when you left click it will not be able to drag and adjust. It will jump to the set amount that you picked over here. Instead, it will just jump to the amount you set when you left click. If you activate a line to target, instead of expanding out, it will expand towards the area it into sex. If you turn on additive area, it will collapse in on itself towards the middle and make a capital B. And constant width just tries to keep the space in between each segment as equal as possible. Hope that helps and as always, hope you have a fantastic day and I'll see you around.