The fastest way to contrain a scetch is jusing the dimention icon with lightning on top of it. This icon is is called Automatic dimentions and constraint. This will constrain youre entire scetch youre currently working on.
I would only recomend to juse this command when youre stuck, and cant find out why youre scetch isent fully constraint yet. This is because when you use this without creating dimentions or constrains first. The dimentions you are creating by the icon is going to show up all over the place. You can offcourse edit them after, so they look good.
Youre choise .