When we are given 3 sides, we try to solve the angles first by using the law of cosines cos (A) = [b^2 + c^2 - a^2] / (2 * b * c) cos (A) = [43^2 + 17^2 -27^2] / (2 * 43 * 17) cos (A) = [1,849 + 289 -729] /
<span>
<span>
<span>
1,462 </span></span></span>cos (A) = 1,409 / 1,462 cos (A) =
<span>
<span>
<span>
0.96374829001368 Angle A = 15.475
Now that we have one angle, we next can use the Law of Sines sin(B) / side b = sin(A) / side a sin(B) = sin(A) * sideb / sidea </span></span></span><span>sin(B) = sin(15.475) * 43 / 27 </span><span>sin(B) = 0.26682 * 43 / 27 sin (B) = </span><span>0.424935555555</span> Angle B = 25.147 Degrees Remember the arc sine (<span>0.424935555555) also equals </span>
<span>
<span>
<span>
154.85
</span></span></span>Finally, calculating the third angle is quite easy Angle C = 180 - Angle (A) - Angle(B) Angle C = 180 - 15.475 - 154.85 Angle C = 9.675
