Can anyone find the length of side x in simplest radical form with a rational denominator?

This is a 30-60-90 triangle. With this special template, the hypotenuse is always twice as long as the shorter leg. Put another way: the shorter leg is half as long as the hypotenuse. So the shorter leg is 4/2 = 2 units long.

The longer leg is equal to sqrt(3) times the short leg. The long leg is 2*sqrt(3) units long which is the final answer.

7. d. 64

8. i. 32

9. c. 125

10. j. none of the above

11. d. 81

12. i. 216

13. e. none of the above

14. g. 240

15. e. none of the above

16. g. 32

17.   e. none of the above