Assignment:
In the triangle with sides a= 21 cm, b=45cm, and c = 60 cm, where the angle gamma is between the sides a and b, the angle beta between the sides a and c, and the angle alpha between sides b and c.
a) Calculate the angle gamma in degrees by using the Law of cosines.
b) Calculate the angles alpha and beta (in degrees) using the Law of Sines.
c) Check that the sum of the angles is 180 degrees.
Provide complete and step by step solution for the question and show calculations and use formulas.