• #### Area of a Sector - Concept

##### Math›Geometry›Area
How to derive the formula to calculate the area of a sector in a circle.
• #### Tangent Segments to a Circle - Problem 3

##### Math›Geometry›Circles
How to calculate the measure of an intercepted arc formed by two tangents drawn from the same point.
• #### Radian Measure of Angles - Problem 1

##### Math›Precalculus›Trigonometric Functions
How to measure a central angle of a circle when the radius and the length of the intercepted arc are given.
• #### Radian Measure of Angles - Problem 1

##### Math›Trigonometry›Trigonometric Functions
How to measure a central angle of a circle when the radius and the length of the intercepted arc are given.
• #### Angles in Semicircles and Chords to Tangents - Problem 1

##### Math›Geometry›Circles
How to find the missing angles in an angle inscribed in a semicircle.
• #### Similar Triangles in Circles and Right Triangles - Problem 1

##### Math›Geometry›Similarity
How to find missing side lengths of triangles in a circle.
• #### Similar Triangles in Circles and Right Triangles - Concept

##### Math›Geometry›Similarity
How to determine if two triangles in a circle are similar and how to prove that three similar triangles exist in a right triangle with an altitude.
• #### Similar Triangles in Circles and Right Triangles - Problem 2

##### Math›Geometry›Similarity
How to find missing side lengths in a right triangle with an altitude drawn from the right angle.