The MnemonicEdit
SohCahToa is a mnemonic for remembering how to use sines cosines and tangents to compute lengths in right angle triangles.
Trigonometric definitionsEdit
This triangle has sides a and b. The angle between them, C, is a right angle. The third side, c, is the hypotenuse. Side a is opposite angle A, and side b is adjacent to angle A.
Applying the definitions of the functions, we have:
 or opposite side over hypotenuse
 or adjacent side over hypotenuse
 or opposite side over adjacent side
This can be memorized using the mnemonic 'SOHCAHTOA' (sin = opposite over hypothenuse, cosine = adjacent over hypotenuse, tangent = opposite over adjacent).
Video LinkEdit
These links from the Khan Academy are useful for this topic.
 Basic Trigonometry SohCahToa (sin and cosine)
 Basic Trigonometry II SohCahToa (starting with tan)
Exercises: (Draw a diagram!)Edit
Exercise: Find sin cos and tan

Exercise: Find a side
