In a triangle ABC, the law of cosines can be illustrated using the rules found in the attached image.
Now, applying this rule to the given triangle, we can calculate the measure of each angle as follows: cos(r) = (s^2 + t^2 - r^2) / (2st) = (9^2 + 6^2 - 14^2) / (2*9*6) = -0.73148 angle r = 137.01 which is approximately 137 degrees
cos(s) = (r^2 + t^2 - s^2) / (2rt) = (14^2 + 6^2 - 9^2) / (2*14*6) = 0.8988 angle s = 25.99797 which is approximately 26 degrees
cos(t) = (r^2 + s^2 - t^2) / (2rs) = (14^2 + 9^2 - 6^2) / (2*14*9) = 0.9563 angle t = 16.99 which is approximately 17 degrees
Summing up the calculated angles: sum = 137 + 26 + 17 = 180 degrees which is the sum of the angles of the triangle
