Trigonometry Rules

We can all use log tables to look up these rules, but I am going to show you one method that will hopefully speed up your trigonometry.
Sin, Opposite, Hypotenuse, Tan, Adjacent, Cos.

There are several methods to remember this, when I was in school my maths teacher said it like this:
So, tow a car!
SOH (So) TOA (Tow A) CAH (Car)

My favourite one and it always sticks in my head is this one:
Some Old Hag Carries A Heavy Tin Of Apples

So now you can fiques it out easily

SOH = Sin of Opposite over Hypotenuse

CAH = Cosine of Adjacent over Hypotenuse

TOA = Tan of Opposite over Adjacent

Another Way:

S illy Old Harry Had A H andful Of Apples


Two Old Angels
Sitting On High
Chatting About Heaven


Oh hell another hour of algebra
Oh hell——–opposite ovr hypoteneuse
Another hour——–Adjacent ovr hypoteneuse
Of algebra———opposite ovr adjacent

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9 Responses to “Trigonometry Rules”

  1. We learned it as

    sin = opp/hyp
    cos = adj/hyp
    tan = opp/hyp

    Reminds me of a Native American name kind of… Chief Sohcahtoa.

  2. “SOH = Sin of Opposite over Adjacent”

    A little tweak is in order. SOH should be SIN = Opposite over Hypotenuse.

    At least that’s what Chief Sohcahtoa told me.

  3. Correction made, thanks for pointing it out Rich,


  4. IN INDIA we have one in the this form (though in HINDI)

    — —– —–

  5. IN INDIA we have one trick in the this form (though in Hindi)
    Sin Cos Tan
    P akistan B hukha P yasa
    H industa H ara B hara
    cosec sec cot

  6. Great stuff. I am going to require some time to think over your post=)

  7. We've all had to learn it as SohCahToa as well. There wasn't a clever little mnemonic to remember it though, damn it. Great post!

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