Question

In triangle ABC, <B is a right angle and m<A = 40. Given that AC = 15, what is AB to the nearest tenth?

Answer 1

11.5. See below.

Explanation:

I think this is what you mean, see diagram below:

You can use the definition of cosine.

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

`cos 40 =(AB)/15`

so ,
`AB = 15 cos 40`

`cos 40 = 0.766`

`AB = 15 * 0.766 = 11.49 = ~ 11.5` to nearest tenth.