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# Right triangles & trigonometry

## Pythagorean theorem

Learn
Intro to the Pythagorean theoremIntro to the Pythagorean theorem 2Pythagorean theorem word problem: fishing boatPythagorean theorem examplePythagorean theorem word problem: carpetPythagorean theorem with isosceles triangleIntroduction to the Pythagorean theoremPythagorean theorem II
Practice
Pythagorean theorem challengeGet 3 of 4 questions to level up!

## Pythagorean theorem proofs

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Garfield's proof of the Pythagorean theoremBhaskara's proof of the Pythagorean theoremPythagorean theorem proof using similarityAnother Pythagorean theorem proof

## Special right triangles

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

## Introduction to the trigonometric ratios

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Intro to the trigonometric ratiosTrigonometric ratios in right trianglesHypotenuse, opposite, and adjacentTrigonometric ratios in right triangles
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 trigonometrySolving for a side in right triangles with trigonometry
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
Practice
Solve for an angle in right trianglesGet 3 of 4 questions to level up!

## Modeling with right triangles

Learn
Right triangle word problemAngles of elevation and depressionRight triangle trigonometry review
Practice
Right triangle word problemsGet 3 of 4 questions to level up!

## Trigonometric ratios & similarity

Learn
Triangle similarity & the trigonometric ratiosTrig challenge problem: verify identitiesTrig challenge problem: trig values & side ratios

## Sine & cosine of complementary angles

Learn
Sine & cosine of complementary anglesUsing complementary anglesTrig word problem: complementary angles

## Law of sines

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

## Solving general triangles

Learn
Trig word problem: starsLaws of sines and cosines review
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.