Question

With a 45 degree right angled triangle, you get the sides being 1, 1 and sqrt 2. What about when you get a 20 degree right angled triangle? How do you find the hypotenuse?

Answer 1

If you know one of the sides (adjacent or opposite)
You can use Cosine or Sine to find the hypotenuse.

Answer 2

Yeah I knew that, I just thought it could be determined using square roots?

Answer 3

You mean Pythagoras' theorem?
For that you need to know both the value of the adjacent and opposite.

Answer 4

ok thanks, so there is no other way to do it without knowing one of the sides?

Answer 5

You need at least one of the sides.

Answer 6

If the triangle is not right-angled (actually works if it is also), you can look up the sine rule and cosine rule.

Answer 7

So if you have a trapezoidal channel with a base of 10m and the side slope is 20 degrees to the horizontal, you can determine the length of the side slope by using 10Tan 20 degrees= 3.64m. is that correct?

Answer 8

Could you draw it out and label it clearly?

Answer 9

You need either o or a.
But if the trapezoid is symmetrical, then if you have y, you can find a.