Answer:
242.7
Step-by-step explanation:
The law of cosines says that if we have tirangle of the form
then
![c^2=a^2+b^2-2ab\cos C](https://img.qammunity.org/2023/formulas/mathematics/high-school/7xuakf37j2toz2151r22q5nwlfcp4icl35.png)
now in our case a = 254, b = 102, and C = 72; therefore, the above equation gives
![c^2=254^2+102^2-2(254)(102)\cos 72^o](https://img.qammunity.org/2023/formulas/mathematics/college/ydgyxhav7969qv65tctyic1kkf89g7dswt.png)
which gives
![c^2=74920-51816\cos 72^o](https://img.qammunity.org/2023/formulas/mathematics/college/vp03ogqt54zlyvsukg5o027g7flkgty29w.png)
![c^2=74920-16012.02458](https://img.qammunity.org/2023/formulas/mathematics/college/4vykzh651bb4alpuw8bpbb53oznxdp7v60.png)
![c^2=58907.96](https://img.qammunity.org/2023/formulas/mathematics/college/37uukqaxbzzi42xv8i5l8z7qs5mf7n80mp.png)
taking the square root of both sides gives
![c=\sqrt[]{58907.96}](https://img.qammunity.org/2023/formulas/mathematics/college/5xxntk2xtdbsbafynaub8aojotg70lm0n9.png)
![c=242.7](https://img.qammunity.org/2023/formulas/mathematics/college/3xbmma82nocs48sutjje8dvcy7folixq6y.png)
which is our answer!