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Most trigonometry students look at triangles on a flat surface. However, people from ancient astronomers to modern navigators calculated the arc lengths and angles of triangles on a sphere. They used ...

Please provide your email address to receive an email when new articles are posted on . NEW YORK — Surgeons need to pay particular attention to angle kappa and spherical aberration when selecting ...

The shortest distance between two points is a straight line. This is one of the basic principles of Euclidean geometry. But we live on a spherical Earth, so we cannot travel the straight line path ...