Calculating Cos inverse to find angle degree

Question

So, right now I am trying to calculate the angles of a right triangle using the inverse of Cosine. However, I don't really know how to do it. I know the equation, just not how to convert into code. The equation would be:: Cos-1(A/C); However, that does not seem to work in Java. I also tried

angleX = (int) Math.acos(sideC / sideA);

Doesn't work? Of course it does. You realize that every language uses radians instead of degrees for angles, right? Shouldn't angles be doubles and not ints? Java is fine; it's your understanding that is lacking. — duffymo, Apr 29 '16 at 14:11
main problem is you cast it to int .so if it is 0.x then you get 0 .do you want the degrees instead of radians? — Madhawa Priyashantha, Apr 29 '16 at 14:19

score 2 · Accepted Answer · answered Apr 29 '16 at 14:15

If sideC and sideA were integers, one would have integer division (2 / 3 == 0). If you do not expect a result in radians, but degrees, a conversion is needed. As double is an approximation, use round too.

if (sideA == 0) { ... }
angleX = (int) Math.round(
        Math.toDegrees(Math.acos(((double)sideC) / sideA)));

Calculating Cos inverse to find angle degree

1 Answers1