Definition of mathematics given by different mathematicians..

Basic concepts of trigonometry.

Trigonometry, as the name might suggest, is all about triangles.

More specifically, trigonometry is about right-angled triangles, where one of the internal angles is 90°. Trigonometry is a system that helps us to work out missing sides or angles in a triangle.

• The right angle is indicated by the little box in the corner.
• The other angle that we (usually) know is indicated by θ.
• The side opposite the right angle, which is the longest side, is called the hypotenuse.
• The side opposite θ is called the opposite.
• The side next to θ which is not the hypotenuse is called the adjacent.