horizontal vertical constrain

[권경범]

There are two ways to apply horizontal/vertical constrain
To select and insert point and point
To select a line
However, if you have a point preselected and you want to apply horizontal and vertical constraints, you are limited by selecting the point and the point. 
If you choose a point However, if you select a line, you want it to be placed in a horizontal/vertical constraint that is entered into the line.