Changing Dim Arc inplace

 From:  Phiro
11052.7 
Hi,

my 2 cents...

Construct the vertical line of 92,0 A
Construct the horizontal of 19.08 B

Construct the pink line (C) with 38,00 length from left point of sgment B and touching segment A

Construct a circle with radius 38 and center the bottom end of C
Construct a circle with radius 66 (38+28) and center the bottom end of C

This last circle cut the axis. The point generated with axis and last circle permits to construct a circle with 28 for radius tangent to the other circle.