Tuning is also a clue. A ukulele tuned D G B E is likely a baritone. Soprano, concert and standard tenor ukuleles are commonly tuned g C E A.
Baritone ukulele strings aren't the same as the other sizes. Our baritone sets are designed for D G B E tuning and use two wound lower strings with two unwound higher strings.
Classical guitar strings aren't a substitute for ukulele strings, or the reverse. Both often use nylon, but they're built and gauged for different instruments, tunings and scale lengths.