Precision is more like consistency. Take a rifle range for example. Sure, all the shots may be off centered, but if they're tightly grouped together, it shows that the shooter had precision in their shooting. Accuracy is how close to spot on the attempts or shots generally are. They would end up more towards the center, but a little more spread out.
Let the angles be x and (180-x).
Let 2x = 180-x.
Then 3x = 180, and x = 60. One angle is 60 degrees and the other is 180-60, or 120, degrees.
(x,y)=(64/81, 70/81) I can provide a description if needed. I used the process of elimination.