In the diagram below, points a and b represent two lakes. how far apart are the lakes?
131.5 ft
456.3 ft
474.6 ft
633.9 ft

I saw the image that should have been posted with this word problem.

It formed a triangle:
Where:
side 1 = 560 ft
side 2 = 350 ft
side 3 = missing info. the distance.
angle given opposite the missing side = 160° - 75° = 85°

We will use the law of cosine to solve for the distance.

c² = a² + b² - 2ab cos(C)
c² = (560ft)² + (350ft)² - 2(560ft)(350ft) cos(85°)
c² = 313,600ft² + 122,500ft² - 392,000ft² (0.087)
c² = 436,100ft² - 34,165ft²
c² = 401,935 ft²
√c² = √401,935ft²
c = 633.98 ft  the last option.