This is a 30-60-90 right triangle. Divide the length of the longer leg by the square root of 3 to get the length of the shorter leg.
[tex] \dfrac{7 \sqrt{3}}{ \sqrt{3}} [/tex]
[tex]=7[/tex]
Multiply that by 2 to get the length of the hypotenuse.
[tex]7*2=\boxed{14}[/tex]
The value of w is 14, which is the last choice. Hope this helps! :)