Trigonometry can be used to find the length of a side in a triangle. Trigonometry close trigonometryThe study of sides and angles in triangles. can be used to find a missing side in a right-angled ...

A triangle is a polygon. It is a closed 3-sided shape made up of straight lines. The ‘tri-’ part of the word triangle means three. A triangle has 3 sides and 3 angles. Interior angles are the angles ...