Let's say you have many similar parts and wish to align them the same way. 2D Tools | Orient Faces may work, however it only aligns each part individually, and doesn't take other shapes into account. A faster way is to align the parts by similarity:

qt_similarity1.png

First, select a single part, drag it to leftmost side, and align it the way you want:

qt_similarity2.png

Then, select all similar parts, and click 2D Tools | Align Selection | By Similarity:

qt_similarity3.png

This will align all parts so that are orientated similarly to the leftmost part. You may also use 2D Tools | Orient Faces afterwards, so each part is perfectly aligned vertically or horizontally:

qt_similarity4.png

That's it! If you have any other questions about aligning parts by similarity, please let us know.