Art of Problem Solving
Art of Problem Solving: Angles in a Triangle Part 2
Video tutorial uses problems to reinforce understanding of angles in a triangle. (Part 2) [6:23]
PatrickJMT
Patrick Jmt: The Law of Cosines
This video provides the formula for the 'Law of Cosines' and one 'applied' example is shown. [4:58]
Khan Academy
Khan Academy: Ca Geometry: More on Congruent and Similar Triangles
Worked examples of similar and congruent triangles.
Khan Academy
Khan Academy: Triangle Similarity & the Trigonometric Ratios
Sal explains how the trigonometric ratios are derived from triangle similarity considerations.
Khan Academy
Khan Academy: Trig Word Problem: Complementary Angles
Sal solves a problem about a submerged pyramid using the fact that the sine of an angle is equal to the cosine of its complementary angle.
Khan Academy
Khan Academy: Proving Slope Is Constant Using Similarity
Sal uses a clever proof involving similar triangles to show that slope is constant for a line.
Khan Academy
Khan Academy: Geometry Word Problem: A Perfect Pool Shot
Sal uses triangle similarity to plan the perfect shot in a pool game.
Khan Academy
Khan Academy: Using Similar & Congruent Triangles
Sal uses the similarity of triangles and the congruence of others in this multi-step problem to find the area of a polygon.
Khan Academy
Khan Academy: Challenging Similarity Problem
Interesting similarity problem where we don't have a lot of information to work with.
Khan Academy
Khan Academy: Using Complementary Angles
Sal solved the following problem: Given that cos(58 degrees)=0.53, find sin(32 degrees).
Khan Academy
Khan Academy: Sine & Cosine of Complementary Angles
Sal shows that the sine of any angle is equal to the cosine of its complementary angle.
Khan Academy
Khan Academy: Trig Word Problem: Stars
Sal solves a word problem about the distance between stars using the law of cosines.
Khan Academy
Khan Academy: Solving for a Side With the Law of Cosines
Learn how to use the law of cosines to find the missing side length of a triangle when given two side lengths and the contained angle measure.
Khan Academy
Khan Academy: Proof of the Law of Cosines
Sal gives a simple proof of the Law of cosines.
Sophia Learning
Sophia: Using Similar Triangles to Make Indirect Measurements
This lesson explains why similar triangles can be used to make indirect measurements, and provides an example.
Sophia Learning
Sophia: Using Triangles to Find the Sum of Interior Angles
This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.
Sophia Learning
Sophia: Using Triangles to Find the Sum of Interior Angles
This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.
Sophia Learning
Sophia: Using Triangles to Find the Sum of Interior Angles
This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.
Sophia Learning
Sophia: Using Triangles to Find the Sum of Interior Angles
This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon.
Sophia Learning
Sophia: Relationships of Trigonometric Functions: Lesson 3
Relationships among the six trigonometric functions are explored in this lesson. It is 3 of 4 in the series titled "Relationships of Trigonometric Functions." Includes short quiz. [4:46]