# How is trigonometry used in astronomy?

##### 1 Answer

Trigonometry is essential for astronomy, Besides 2-D trigonometry relating to triangles, spherical trigonometry, relating to spherical triangles, is also important in astronomy.

#### Explanation:

The planets' surfaces are nearly spherical.

Points on surface can be spotted by using spherical polar co-ordinates

Three great circles on the planet's surface form a spherical triangle. . Spherical trigonometry formulas connect the lengths of arcs of this triangle with the angles of the triangle. There is similarity between these formulas and 2-D formulas.

The ships over seas and the planes, at the top altitudes, trace nets of spherical triangles..