I'm sorry, but as you as saw in the
Read Before Posting thread, we don't do student's homework for them. That's your job. We're more than happy to provide hints. That said, I'd begin by noting that a kite can be divided into four right triangles. Looking at the two larger triangles, you know the hypotenuse of each of them (your given
k) and one of the legs (your unknown
x). You can use the Pythagorean Theorem to find an expression for the other leg in terms of
x. Then do a similar process for the two smaller right triangles. Now you continue from here...