Planar face direction

Need help? We are here.
1

IMG_0366

Hi, I am figuring how to draw planar face the way I want. For instance, I pull a line up, a planar face will be there. In my pic, how to draw a planar face 90 degrees to A and 90 degrees to B.

Furthermore, after rotating face A, I couldn’t select the little trangle on face B. Thank you all

2

The solution for this will be the upcoming construction geometry feature. It will be included in the next release.

3

Thank you !!!