In the triangle ABC, the opposite sides of angles a, B and C are a, B, C, Tana is one fourth and tanb is three fifths. Find the size of angle C. if C is equal to number 17, find the length of side a

tanC=tan(π-A-B)=-tan(A+B)=-（tanA+tanB）/(1-tanAtanB)=-1
So the angle c is 135 degrees
Tana is equal to a quarter, so we can calculate Sina = 1 / radical 17
A / Sina = C / sinc from sine theorem
We get a = root 2

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