bevel length 1 and 2 given angled length

I am drawing a blank as to how to enter the dimensions for a bevel when have the angled bevel length.  I have a length of 13.488 and a width of 14.88 with a bevel length of 7.906 please see attached.  I am trying to get the "straight bevel" that is in the image and not the rounded corners or radius that can be added "if needed"

It is not possible to use the angled bevel length as input directly. Assuming you want a 45° bevel on lines meeting at 90°, the input for bevel length 1 and 2  would be: x/sqrt2 , x being your desired angled bevel length. But it doesn't work, or I don't know the proper syntax. Somebody else?
It works if you type in the value for square root of 2 manually with an accuracy you think is sufficient, 1.4142135...

Thank you so much!!!! I was able to get the angled length to 7.9061.