Bearings & Distances

\text{east} = d\sin(\theta),\; \text{north} = d\cos(\theta)

Distance O to B12.8 km

Bearing of B from O098.7°

Back bearing (O from B)278.7°

Leg 1 · bearing60 °

Leg 1 · distance10 km

Leg 2 · bearing150 °

Leg 2 · distance8 km

Get the direct distance from O to B to at least 15 km
Make B lie due east of O (resultant bearing of about 090°)
Sail 10 km due north (000°), then 10 km due east (090°) — find the direct distance back (10√2 ≈ 14.14 km)
Make the back bearing from B to O exactly 040° (so B lies on a bearing of 220° from O)
Align both legs in roughly the same direction to push the direct distance above 20 km