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Right triangles & trigonometry

Pythagorean theorem

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Intro to the Pythagorean theorem
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Intro to the Pythagorean theorem 2
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Pythagorean theorem word problem: fishing boat
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Pythagorean theorem example
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Pythagorean theorem word problem: carpet
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Pythagorean theorem with isosceles triangle
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Introduction to the Pythagorean theorem
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Pythagorean theorem II
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Practice
Use Pythagorean theorem to find right triangle side lengthsGet 5 of 7 questions to level up!
Use Pythagorean theorem to find isosceles triangle side lengthsGet 5 of 7 questions to level up!
Pythagorean theorem challengeGet 3 of 4 questions to level up!

Pythagorean theorem proofs

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Garfield's proof of the Pythagorean theorem
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Bhaskara's proof of the Pythagorean theorem
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Pythagorean theorem proof using similarity
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Another Pythagorean theorem proof
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Special right triangles

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Special right triangles intro (part 1)
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Special right triangles intro (part 2)
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30-60-90 triangle example problem
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Special right triangles proof (part 1)
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Special right triangles proof (part 2)
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Area of a regular hexagon
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Special right triangles review
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Practice
Special right trianglesGet 5 of 7 questions to level up!

Introduction to the trigonometric ratios

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Intro to the trigonometric ratios
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Trigonometric ratios in right triangles
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Hypotenuse, opposite, and adjacent
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Trigonometric ratios in right triangles
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Practice
Trigonometric ratios in right trianglesGet 3 of 4 questions to level up!

Solving for a side in a right triangle using the trigonometric ratios

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Solving for a side in right triangles with trigonometry
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Solving for a side in right triangles with trigonometry
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Practice
Solve for a side in right trianglesGet 3 of 4 questions to level up!

Solving for an angle in a right triangle using the trigonometric ratios

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Intro to inverse trig functions
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Practice
Solve for an angle in right trianglesGet 3 of 4 questions to level up!

Modeling with right triangles

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Right triangle word problem
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Angles of elevation and depression
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Right triangle trigonometry review
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Practice
Right triangle word problemsGet 3 of 4 questions to level up!

Trigonometric ratios & similarity

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Triangle similarity & the trigonometric ratios
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Trig challenge problem: verify identities
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Trig challenge problem: trig values & side ratios
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Sine & cosine of complementary angles

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Sine & cosine of complementary angles
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Using complementary angles
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Trig word problem: complementary angles
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Law of sines

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Solving for a side with the law of sines
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Solving for an angle with the law of sines
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Proof of the law of sines
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Practice
Solve triangles using the law of sinesGet 3 of 4 questions to level up!

Law of cosines

Learn
Solving for a side with the law of cosines
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Solving for an angle with the law of cosines
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Proof of the law of cosines
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Practice
Solve triangles using the law of cosinesGet 3 of 4 questions to level up!

Solving general triangles

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Trig word problem: stars
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Laws of sines and cosines review
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Practice
General triangle word problemsGet 3 of 4 questions to level up!

About this unit

Triangles are not always right (although they are never wrong), but when they are it opens up an exciting world of possibilities. Not only are right triangles cool in their own right (pun intended), they are the basis of very important ideas in analytic geometry (the distance between two points in space) and trigonometry.