The area for a rhombus is
![A= (1)/(2)( d_(1) d_(2) )](https://img.qammunity.org/2019/formulas/mathematics/college/p5wnwob1gmnf5ixgdovv1ezobduhuqax10.png)
. We have the area and the length of one of the diagonals, so we fill in accordingly:
![16= (1)/(2) (8x)](https://img.qammunity.org/2019/formulas/mathematics/college/4w2pi9egawm8rwjss7epbql80exdwsexz3.png)
. 8x/2 = 4x, so now we have 16=4x. Divide both sides by 4 to get x = 4. It's not longer than 8, but it's the length of the other diagonal, for sure.