Is there some other ways to deduce resistance from current, than Ohm's Law?

Also, are Kirchoff's laws usually often in conjunction with Ohm's Law, because aren't

$$\sum I=0, \sum V=0$$

slightly useless for practical purposes on their own (without adding Ohm's Law to the above)?

Are there some other ways to deduce resistance from current, than Ohm's Law (e.g. because why'd we assume a linear relationship?)?

Also, are Kirchoff's laws usually often in conjunction with Ohm's Law, because aren't

$$\sum I=0, \sum V=0$$

slightly useless for practical purposes on their own (without adding Ohm's Law to the above)?

Is there some other ways to deduce resistance from current, than Ohm's Law?

Also, are Kirchoff's laws usually often in conjunction with Ohm's Law, because aren't

$$\sum I=0, \sum V=0$$

slightly useless for practical purposes just as they are?

Is there some other ways to deduce resistance from current, than Ohm's Law?

Also, are Kirchoff's laws usually often in conjunction with Ohm's Law, because aren't

$$\sum I=0, \sum V=0$$

slightly useless for practical purposes on their own (without adding Ohm's Law to the above)?