Frame Angles are pretty easy to measure with an electronic angle finder.

First, make sure front and rear tires are inflated to the same pressure. Then set up the bike with the wheels on a flat surface (I use a length of square cross-section extruded aluminum).



Next, put the angle finder on the flat surface and zero it (set angle finder for 0° on the flat surface).



Then place the angle finder on the seat tube and the head tube to find the STA and HTA.