Gary and everyone,

And don't forget what is probably the main reason a DI scale was
put on a trig rule - solving vector resolution or right triangle
problems. (Assuming a rule with DI on the stock, and trig
scales on the slide.)

E.g., imagine the famous 3-4-5 right triangle, and pretend we know
only the length 3 and 4 sides.

- Put the right index over 3 on DI
- Slide cursor over 4 on DI
- Read 36.9 degrees on T

- Now, move cursor to 36.9 degrees on S
- Read 5 on DI

So given any 2 measures of sides or angles (other than the 90 degree
one) of a right triangle, the DI and trig scales let you solve the
rest with a single setting.

Mike Markowski