🔍 Key Concepts

• Lines of position (LOPs) and how they form a fix on a chart • How the angle between two LOPs affects the accuracy of the intersection (the fix) • Why very acute or very obtuse angles between LOPs are less desirable

💭 Think About

• Think about what happens to the size and shape of the ‘error triangle’ when the angle between two LOPs gets closer to a straight line versus when it forms a more balanced angle. • Imagine plotting two LOPs that are almost parallel—would a small plotting error on one line change the fix a little or a lot? • Compare the geometry of two LOPs that cross at different angles: which angle gives the most ‘tight’ and reliable intersection area?

✅ Before You Answer

• Make sure you understand that the best fix means the smallest error area around the intersection of the LOPs. • Consider which angle range (small, medium, or near 180°) gives the least sensitivity to small plotting errors. • Verify in your plotting practice or textbook which approximate angle between two LOPs is considered optimal for a two-line fix.