PreCalculus Section 5.4: Right Triangle Trigonometry

Flashcards covering key concepts and definitions from the lecture on Right Triangle Trigonometry.

Trigonometric Functions

Functions that relate the angles of a triangle to the lengths of its sides.

Cofunctions

Functions that relate the trigonometric functions of complementary angles, such as sin and cos.

Pythagorean Theorem

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

Angle of Elevation

The angle between the horizontal line from the observer’s eye and the line to the object above the observer.

Angle of Depression

The angle between the horizontal line from the observer’s eye and the line to the object below the observer.

Complementary Angles

Two angles that sum to 90 degrees (or π/2 radians).

Sine (sin)

A trigonometric function defined as the ratio of the length of the opposite side to the hypotenuse.

Cosine (cos)

A trigonometric function defined as the ratio of the length of the adjacent side to the hypotenuse.

Tangent (tan)

A trigonometric function defined as the ratio of the length of the opposite side to the adjacent side.

Cotangent (cot)

A trigonometric function defined as the ratio of the adjacent side to the opposite side.

Secant (sec)

A trigonometric function defined as the reciprocal of cosine.

Cosecant (csc)

A trigonometric function defined as the reciprocal of sine.

Hypotenuse

The longest side of a right triangle, opposite the right angle.

Adjacent Side

The side of a right triangle that forms one of the two angles with the hypotenuse.

Opposite Side

The side of a right triangle that is opposite to a given angle.