This week in Math 10 I learned what the mnemonic device SOH CAH TOA means. It is something that is very helpful to use to remember the definitions of the trigonometric functions sine, cosine and tangent.
First we can figure out how to find sine by doing the opposite angle divided by the hypotenuse. Since the O goes before the H in SOH, it means O is the number on the top of the fraction (division).
To find cosine we would do the adjacent side divided by the hypotenuse, since the A in CAH goes before the H.
To find tangent we would do the opposite side divided by the adjacent side, since the O goes before the A in TOA.
The first letters- S, C and T are just there to tell you what function it would be (sine, cosine, tangent).
SOH CAH TOA should be the first thing you write on your paper since it is very helpful, then you should label all the sides of the triangle.
Here is an example of me using SOH CAH TOA to help me find a missing side of a triangle:
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