The angle m can be found by noticing that:
cos m = 22.5/25
That's so because if we divide the triangle formed by the taper into two others, we get two right triangles.
Each right triangle has the angle m, the adjacent leg measuring 22.5 mm, and the hypotenuse measuring 25.0 mm.
So, using the formula for the cosine, we get the above relation. Then, solving this equation, we have:
cos m = 22.5/25
m = arccos 22.5/25
m ≅ 25.84º
Therefore, the angle of the taper is:
2 * m = 2 * 25.84º = 51.68º
Now, in order to convert this result using arc minutes, we need to remember that each 1º corresponds to 60' (60 arc minutes). Thus, we have:
1º --- 60'
0.68º --- x
So, cross multiplying those values, we find:
1º * x = 0.68º * 60'
x = (0.68º/1º) * 60'
x = 0.68 * 60'
x = 40.8'
x ≅ 41'
Therefore, the answer is 51º41'.
