Answer:
155 km
Step-by-step explanation:
As shown:
At Δ BDC which is a right triangle at ∠D
BC = 78 km
m∠CBD = 90° - 64° = 26°
cos ∠CBD = BD/BC
∴ BD = BC * cos ∠CBD = 78 * cos 26° = 70.106 km
Port C is at a distace to the east of A = AO + BD
= 85 + 70.106 = 155.106 km ≈ 155 km to the nearest km
