I am attempting to find the angle of a triangle based on the length of the sides. I have no knowledge of any angles of the triangle.
I am using the equation: b^2 = a^2 + c^2 - 2ac cos B
where ^ denotes power of
B is the angle I am trying to find
b is the length of the side opposite B
a and c are the lengths of th other two sides.
So, if I have the data; b = 5, c = 4, a = 6
25 = 16 + 36 - 2*4*6 cos B
=> 25 = 52 - 48 cos B
=> 48 cos B = 27
=> cos B = 27/48
=> cos B = 0.5625
Is there a method to find B on its own? i.e. inverse of cos B?