Line segment YV of rectangle YVWX measures 24 units. What is the length of line segment YX? 8 units units 12 units units

I assume there is a missing piece of information here, either the area or the perimeter should be given.
I'll just tell you how to solve this type of problems and you can apply using the information in your question.

If YV is the width of the rectangle, then YX will be its length.

Now, if the area is known:
area of triangle = width x length = YV x YX
YX = area / 24

If the perimeter is known:
perimeter of rectangle = 2 (length + width)
perimeter = 2 (YV + YX)
YX = (perimeter / 2) - 24