Alan

As follows:

As follows:

$\sqrt{\frac{4e}{3f}}=\sqrt{\frac{4\times3ef}{9f^2}}=\frac{2}{3f}\sqrt{3ef}\\ \text{or just }\frac{2\sqrt{3ef}}{3f}$

Try looking on the general Answers page, rather than selecting this specific question.

As follows:

Can you take it from here?

Here are three possible methods you could use, together with a graph of the triangles to help:

You could use the on-line graphing capability of Desmos:  https://www.desmos.com/calculator

You would enter: y= sin(x)-cos(x) {0≤x≤2*pi}

As follows:

As follows:

There is no unique answer here, as you can see by factoring the number, which you can do here on the webcalc2.0 calculator:

This should help: