I find it very interesting.
The length of what?
trigonometry
Trigonometry is used to find the properties of triangles and Pythagoras' theorem is used to find the lengths and angles of right angle triangles.
Mechanics use trigonometry to find angles mostly used in body or chassis work.
Use trigonometry.
By using trigonometry
Trigonometry can be used to find the heights of buildings when paired with a sextant (a device for measuring angles from the buliding)
Trigonometry is used to find the distance and angle of atoms that are bonding. Oh this is for chemistry by the way hope this was helpful. :)
By using a protractor or using trigonometry
By measuring it or using trigonometry.
It is used to find measures of angles and lengths of sides in triangles.
Navigation takes place on the surface of a sphere, and it involves angles and distances. Spherical trigonometry was developed from plane trigonometry so that navigators could find their away over the Earth's surface.