Trigonometry Review

Right Triangle Trigonometry Angles are often represented by Greek letters: a alpha b beta  gamma  theta  phi d delta R x y Pythagorean theorem The square of the hypotenuse is equal to the sum of the squares of the other two sides.

Right Triangle Trigonometry hyp adj opp q The sine value of a right triangle is equal to the ratio of the length of the side opposite the angle to the length of the hypotenuse of the triangle. The cosine value of a right triangle is equal to the ratio of the length of the side adjacent to the angle to the length of the hypotenuse of the triangle. The tangent value of a right triangle is equal to the ratio of the length of the side opposite the angle to the side adjacent to the angle.

R = 20 m is hypotenuse. Thus, Pythagoras’ Theorem: Example 5: What is the distance x across the lake, and what is the angle q? R = 20 m is hypotenuse. Thus, Pythagoras’ Theorem: x 20 m 12 m q x = 16 m q = 53.10

Trigonometry Review You are expected to know the following: y = R sin q y x R q x = R cos q R2 = x2 + y2