So many responders, so I’m not sure who’s dimensions you are looking for.
For mine, the side beds, or legs of the “U” are approximately 3 feet wide x 18 feet long. One leg is approximately 22” deep and the other is 15” deep. The base of the “U” is 6 feet wide x 12 feet long x 22” deep.
Peppers and such are in the deeper/taller leg, tomatoes in the shorter leg. Squash, zucchini, and cucumbers in the base section. I’ll grab some current pictures. Everything has taken off like crazy. Eating squash and zucchini several times a week from only two plants of each.