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# Right angle watch

1. Hello Folks
On a right angled triangle is it possible to work out the degrees of an angle with out using a protractor if A,B and the hypotenuse are known measurements?

Thanks

Simon
2. use pythagorus? or sine/cosine rule?
3. (Original post by qam)
use pythagorus? or sine/cosine rule?
Could you explain in more detail please an example would be great
4. Pythagoras theorem to find hypotenuse (c) a^2 + b^2 = c^2 ( then square root c to find hyp) now you have 3 sides. To find an angle you use Cos A = b2 + c2 - a2
_____________
2bc
Could you explain in more detail please an example would be great
Give us a question and we will tell u how to go about it. Preferably a picture of the question/diagram
6. (Original post by Ibrahimmmm3939)
Pythagoras theorem to find hypotenuse (c) a^2 + b^2 = c^2 ( then square root c to find hyp) now you have 3 sides. To find an angle you use Cos A = b2 + c2 - a2
_____________
2bc
Hello and thank you

I have just learn t Pythagoras theorem to find the hypotenuse. I will now try the Cos part you have given

Simon
7. don’t forget to inverse cosine the answer to the Cos A part to get the angle on its own. Inverse cosine is (cos^-1 on your calculator)

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