Answer:
x = 36 km
Explanation:
The triangle is a right triangle. To find x, apply Pythagorean theorem which is given as: c² = a² + b²
c = hypotenuse/longest leg = 45 km
a = x
b = 27
Thus:
45² = x² + 27²
2,025 = x² + 729
2,025 - 729 = x²
1,296 = x²
√1,296 = x
36 = x
x = 36 km