The largest side is opposite the largest angle, the smallest side is opposite the smallest angle. 11+5+2=18, and 180/18=10, so the angles are
![A=110^\circ, B=50^\circ, C=20^\circ](https://img.qammunity.org/2019/formulas/mathematics/high-school/7o1kjgnisy4660lq4jrirlkyuwjsspigad.png)
The longest side is opposite the largest angle, so
![a = 5.5 \textrm{ cm}](https://img.qammunity.org/2019/formulas/mathematics/high-school/menap7hmzvh0wnr0somvv1ywnpd4fmzk6k.png)
The shortest side is opposite the smallest angle, so
.
The Law of Sines says
![(c)/(\sin C)=(a)/(\sin A)](https://img.qammunity.org/2019/formulas/mathematics/high-school/3xi7whphixxpzdl4ammgnd6guuaqifa0cg.png)
![c=(a \sin C)/(\sin A)](https://img.qammunity.org/2019/formulas/mathematics/high-school/o9iy7he7piabk5hbmq179il16wuhjo1ox2.png)
![c=(5.5 \sin 20^\circ)/(\sin 110^\circ) \approx 2.00184](https://img.qammunity.org/2019/formulas/mathematics/high-school/uhxb2yo2mdjoronn9wz06h9t6nx0mc9c00.png)
Answer (rounded): 2.00