Introduction+to+Trigonometry+and+the+Unit+Circle

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A submission for the Khan Academy Talent Search. #khanacademytalentsearch @ https://www.khanacademy.org/talentsearch

Introduces sines and cosines as the y and x coordinates of a point with polar coordinates of 1 and 𝛳. Uses Pythagoras' Theorem to calculate the sines and cosines of angles which are mulltiples of 45° and 30°.

Traditional SOH and CAH type problems can be introduced following this, by scaling up to r and 𝛳, and by presenting problems without reference to Cartesian coordinates, and by changing orientation.