Question

In the right - angled triangle shown, cos 0 equal to?

Answer 1

In a rigth triangle:

θ

The cosine ratio is:

`\cos\theta=(adjacent)/(hypotenuse)`

In the triangle given, we don't know the length of the adjacent leg to θ. We can find it using the pythagorean theorem:

`hypotenuse^2=adjacent^2+opposite^2`

In this case:

hypotenuse = 13

opposite = 12

Then:

`13^2=adjacent^2+12^2`

And solve:

`\begin{gathered} adjacent^2=13^2-12^2 \\ . \\ adjacent^2=169-144 \\ . \\ adjacent=√(25) \\ . \\ adajcent=5 \end{gathered}`

Now, we can find the cosine ratio:

`\cos\theta=(5)/(13)`