• #### Central Angles and Intercepted Arcs - Concept

##### Math›Geometry›Circles
How to define a central angle and find the measure of its intercepted arc; how to describe the intercepted arcs of congruent chords.
• #### Evaluating Sine and Cosine at Other Special Angles - Concept

##### Math›Precalculus›Trigonometric Functions
How to measure the sine and cosine of 150.
• #### Radian Measure of Angles - Problem 4

##### Math›Precalculus›Trigonometric Functions
How to find the arc length and area of a sector when the central angle is given in radians or degrees.
• #### Evaluating Sine and Cosine at Other Special Angles - Problem 1

##### Math›Precalculus›Trigonometric Functions
How to measure the sine and cosine of -135?.
• #### The Angle Between Planes - Concept

##### Math›Precalculus›Vectors and Parametric Equations
How to find the angle between planes, and how to determine if two planes are parallel or perpendicular.
• #### Other Forms of the Cosine Double-Angle Formula - Concept

How to derive two more cosine double-angle formulas.
• #### Other Forms of the Cosine Double-Angle Formula - Concept

How to derive two more cosine double-angle formulas.
• #### Evaluating Sine and Cosine at Other Special Angles - Problem 3

##### Math›Trigonometry›Trigonometric Functions
How to measure the sine and cosine of -5?/3.
• #### Evaluating Sine and Cosine at Other Special Angles - Problem 3

##### Math›Precalculus›Trigonometric Functions
How to measure the sine and cosine of -5?/3.
• #### Radian Measure of Angles - Problem 2

##### Math›Trigonometry›Trigonometric Functions
How to convert to radians when degrees are given.
• #### Other Forms of the Cosine Double-Angle Formula - Problem 1

How to use the cosine double-angle formulas to derive the power reduction formulas.
• #### Radian Measure of Angles - Problem 2

##### Math›Precalculus›Trigonometric Functions
How to convert to radians when degrees are given.
• #### Evaluating Sine and Cosine at Other Special Angles - Problem 2

##### Math›Precalculus›Trigonometric Functions
How to measure the sine and cosine of 11*pi/6.
• #### Constructing an Angle Bisector - Concept

##### Math›Geometry›Constructions
How to define and construct an angle bisector.
• #### Other Forms of the Cosine Double-Angle Formula - Problem 1

How to use the cosine double-angle formulas to derive the power reduction formulas.
• #### The Angle Between Vectors - Problem 2

##### Math›Precalculus›Vectors and Parametric Equations
How to determine whether two vectors are perpendicular or parallel.
• #### Evaluating Sine and Cosine at Other Special Angles - Problem 2

##### Math›Trigonometry›Trigonometric Functions
How to measure the sine and cosine of 11*pi/6.
• #### Angle Bisectors and Opposite Side Ratios - Problem 1

##### Math›Geometry›Similarity
How to find a missing length created by a median in a triangle using a proportion.
• #### Central Angles and Intercepted Arcs - Problem 4

##### Math›Geometry›Circles
How to find the measure of an arc created by the vertices of an inscribed regular polygon.
• #### Central Angles and Intercepted Arcs - Problem 3

##### Math›Geometry›Circles
How to find the measure of an intercepted arc given the measure of two arcs.