[Math] Solving obtuse triangle given angles and 1 side

trianglestrigonometry

This probably seems like a very basic question but it has been along time since I did any trigonometry…

I am trying to calculate the sides of an obtuse triangle given the 3 angles:

$$\angle A = 38.6642, \angle B = 136.56, \angle C = 4.775$$

and the side $a = 10.18$ (opposite $\angle A$).

I have tried the Sine Rule:

$$\frac{a}{\sin(A)} = \frac{b}{\sin(B)} = \frac{c}{\sin(C)}$$

thus yielding

$c = \sin(C) \cdot \dfrac{a}{\sin(A)}$ , but with the triangle I have, that gives me $-12.3948…$

What have I misunderstood? How can I calculate the sides?

Best Answer

I was using MATLAB and the sin() function requires radians. To convert degrees to radians the degtorad() function can be used.