Do you know, that… ?

You can very easily insert a plane through the center of the cylinder. To do this you need to (predefined method) select an existing plane through the center and with CTRL the face of the cylinder.

After enabling the command Płaszczyzna a preview will automatically appear, and the selections will be completed as first and second reference. The program will choose Perpendicular and Arkuskosinus and a tangent plane appears on one side.

To change the page, select / deselect this option Reverse offset.

In turn, changing the default selection from Perpendicular to Parallel results in insertion of a parallel and tangent plane at the same time.

If you want to rotate the plane around the side of the cylinder (or hole), select an option At an angle and enter the expected value.

Wanting to insert a plane in the center, but rotated by a given angle, select Temporary axis and a selected plane through the center. In the plane settings, change the default perpendicular mode to At an angle and ready.