A triangle has sides A, B, and C. Sides A and B are of lengths #7# and #5#, respectively, and the angle between A and B is #(5pi)/8 #. What is the length of side C?
Well this is a very tricky one, i wish i can draw the Triangle to explain better, but with the theory i hope you will understand..
Firstly Note that the Angle is in Radians..
If you observe closely,
Angel between A and B is
You're aware that there are only 3 angels which are
Now again; What is the Angle between
Simple, the answer is
Cause it's a Triangle so the angle is C, since it's in between the two angles..
It's just a trick to push you off course from the desired Answer..
Hence we have as follows;
Before we proceed further, remember first i said Note that the Angle is in Radians..
We must first convert from Radians to Degree..
Using this formula
Now to find c we shall using the Cosine Rule Formula
Imputing your values..