I will chime in that the science idea of "Unit Cancellation" will help in almost all science problems. Let's pick Inches as our "convenient" unit of measure. (People that live in countries with the metric system are going to laugh in disbelief at what we have to do here.)
50 yards x (3 feet/yard) x (12 inches/foot) = 1800 inches "adjacent side" for the base.
10.17 inches is the "opposite side" of the triangle (You can use -10.17 if you like, too)
Tan(A) = Opposite/Adjacent
Inverse Tangent( Tan(A)) = Inverse Tangent (Opp/Adj)
A = .3237177 DEGREES. (Note: find the inverse tangent of 1. That should = 45 degrees or your calculator is in radian unit mode.)
0.3237177 Degrees x (60 minutes/1 degree) = 19.42306 MINUTES of angle.
The deviation from the point of impact from the laser-sight boreline of the barrel is 19.42306 minutes of angle.
There are 60 minutes of angle per degree, and 60 seconds of angle per angular minute. These wacky units are convenient when doing land surveying and considering longitude and latitude back in the days when one had to do all divisions by hand, and before the decimal number system was widely understood. If you want to divide (30 degrees 40 minutes 20 seconds) in half, it's easy to see it's 15 degrees 20 minutes 10 seconds.
With modern electronics, it's simply obsolete. We forget that modern electronics have only been around for about 50 years. In our hobby, we use other inconvenient units like grains of powder, drams (shotgun shells), ounces (shotgun pellets), minutes, yards, miles.. and I am sure more. History going back a couple of hundred years.
To be exact, a Minute of Angle is close to 1" at 100 yards but it's really 1.047 inches per 100 yards but 8.37" at 800 yards. Except we use fractions of inches (just to drive people crazy) and I'd say ".37 is about .375" which everyone knows is 3/8 of an inch. So at 800 yards the difference is 3/8". Maybe not enough for you to care about, but since we pulled out the calculator anyhow, why not do it right?
This way of doing things doesn't use rough approximations, other than rounding off the degrees to 7 decimal places. the inverse tangent function is various places on various scientific calculators or calculator apps.