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Angles and Trigonometry

Overview

– Angle properties of triangles, quadrilaterals and parallel lines

– Interior angles of a polygon

– Exterior angles of a polygon

– Pythagoras’ theorem

– Trigonometry

Example Key Words

Hypotenuse

The longest side of a triangle. It is also the side opposite the right angle.

Pythagoras' Theorem

A theorem stating that in a right triangle the area of the square on the hypotenuse is equal to the sum of the areas of the squares drawn on the other two sides.

Opposite and Adjacent Side Side

The side opposite (opposite) and next to (adjacent) the angle you are dealing with in a triangle (not the right angle)

The Sine Ratio

The sine of an angle in a right triangle is defined as the ratio of the length of the side opposite the angle to that of the hypotenuse.

The Cosine Ratio

The cosine of an angle in a right triangle is defined as the ratio of the length of the side adjacent to the angle to that of the hypotenuse.

The Tangent Ratio

The tangent of an angle in a right triangle is defined as the ratio of the length of the side opposite the angle to that of the adjacent side.