Chapter 2 - Acute Angles and Right Triangles - Section 2.5 Further Applications of Right Triangles - 2.5 Exercises - Page 87: 22

$x\approx 69.5 $ nautical miles

1. $d(AC) = 2.5 hr\times17 knots = 42.5$ nautical miles $d(AB) = 2.5 hr\times22 knots = 55$ nautical miles 2. By Pythagorus theorem $x^2 = 42.5^2 +55^2$ $x = \sqrt {42.5^2 +55^2} \approx 69.5$ nautical miles