The study of Trigonometry with emphasis on Triangles

Trigonometric Functions of Acute Angles

Terminology

· Acute Angle: An angle measuring between 0 and 90 degrees. .

· Obtuse Angle: An angle measuring between 90 and 180 degrees. (.

· (Reflex Angle: An angle measuring more than 180 degrees.)

Notation

Measure of Angle B denoted m or simply . Example = .

Six Trigonometric Functions

Cosine (cos) Secant (sec)

Sine (sin) Cosecant (csc)

Tangent (tan) Cotangent (cot)

Overhead 6.1,pg2

For section 6.1 all of the inputs to the trigonometric functions will be acute angles, all of the outputs will be real numbers. Below the value of is the input value.

Right Triangle Definitions

Theorem: The Right Triangle

In a right triangle, the length of the side opposite the angle is half the length of the hypotenuse.