Final answer:
The angle between a line and a plane is defined using trigonometric ratios and can be expressed in degrees, with degrees being further subdivided into minutes and seconds of arc. In astronomy, these angles can represent the apparent size of objects seen from far away. Knowledge of triangle properties, such as the sum of angles equating to 180 degrees, is foundational in geometry.
Step-by-step explanation:
Defining the angle between a line and a plane involves thinking of a perpendicular from the line to the plane which creates an angle that can be measured. Angles are generally expressed in degrees, minutes of arc, and seconds of arc, where one degree is equal to 60 minutes and one minute is equal to 60 seconds. When calculating angles in trigonometry, trigonometric ratios such as sine, cosine, and tangent are used, and these ratios are dimensionless, meaning they have no units associated with them.
In practical applications, like in astronomy, measuring very small angles such as arcseconds is important, and these measurements can relate to visually recognizable objects like a golf ball viewed from a great distance. Precision measurements can involve small degrees or even minute fractions of a degree, as illustrated by examples given in the Hipparcos web pages.
Lastly, understanding the properties of triangles is fundamental in geometry. Apply this knowledge we know that the sum of the angles in any triangle will always add up to 180 degrees.