Use GUESS method for triangles.
G: Givens
We are given a side length of 6 and 17 and a angle between that, whom is 76.
U: Unknowns
We are trying to find the missing side which is opposite of the given angle.
E: Equations,
whenever we have a non right triangle, given two side and a given angle, we can use law of cosines to find the third side.
![c = \sqrt{ {a}^(2) + {b}^(2) - 2ab * \cos(x) }](https://img.qammunity.org/2023/formulas/mathematics/high-school/fktdrsvwogp1mn6diy68wpk941t9epnxhn.png)
where a and b are the given sides, and x is the angle measure.
S: Solve
We know plug in the values,
![c = \sqrt{ {17}^(2) + {6}^(2) - 2(17)(6) * \cos(76) }](https://img.qammunity.org/2023/formulas/mathematics/high-school/b0624pe7ntgavdt99k2trdluwxoj8mbonx.png)
![c = √(289 + 36 - 204 * \cos(76) )](https://img.qammunity.org/2023/formulas/mathematics/high-school/4fkpue52ancxor6ys2bk4buroccz9hlusy.png)
When solving we get
![c = 12.5234](https://img.qammunity.org/2023/formulas/mathematics/high-school/y3sgw1z91mqg2j30pnkmimtcxyvg7gc14s.png)
S: Solution
Round if you are needed to,
![c = 12.5234](https://img.qammunity.org/2023/formulas/mathematics/high-school/y3sgw1z91mqg2j30pnkmimtcxyvg7gc14s.png)