Trig Question

As long as you get the correct answer you did it right. You got it right.

"Billy G"
 
Wrong answer, Wreck. Use aligned dimension. The hypotenuse is 2.5oo, not the base.

It's simple. SinA*c-c of rolls give you stack height.
 
Thanks for all the replies.
The base (side b) is 2.5" and the angle is 20 degrees.
I think the right answer is .909925 by the formula--I guess I am just missing on how to use the online calculators (putting in the wrong numbers?)

edit: I think it just clicked for me after reading Tony's 1st post again.
 
Hmmm. My 20 year old TI36X calculator returns for 2.5 x sin 20 = 0.855050358. That's the stack of Jo blocks. 2.5 has gotta be the hypotenuse.
 
John, side "b" is totally immaterial. When you sit the sine bar on a surface plate, for example, it may as well be infinitely long. What changes, as Wreck illustrated, is the distance from the bottom of the stationary roll to the roll that is elevated. In the plane represented by the surface plate in my illustration, the distance between the rolls "appears" to get shorter, the only option it has when you rotate it out of a plane parallel with the reference (surface plate or vise, or machine table, etc)BUT, the roll c-c stays the same, no matter what. That's the value you have to know to calculate the stack, which of course varies according to the angle. You can safely ignore the length of side "b".
 
Do the calculations for a 45° angle, and set your protractor up against it, or a 45° angle block. At that severe an angle, the error will be obvious if you use 2.500 for side "b" in the calculations. Then set it using 2.500 as side "c" (hyp) for sin multiplier. It will then match your protractor.

Use the formulas on the second line in your chart. Angle A and side "c" are your knowns.
 
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