You don’t need a tape to find a third. Just like you don’t need one to find a half. If you’re a woodworker, you’ll be using a centre finder. And it’s not hard to make one to find thirds. Just take a plank of wood and put four holes at equal distances, then insert two short dowels into the furthest holes.
You want to show me a tape measure, caliper or micrometer marked in thirds of a millimeter?
You don’t need a tape to find a third. Just like you don’t need one to find a half. If you’re a woodworker, you’ll be using a centre finder. And it’s not hard to make one to find thirds. Just take a plank of wood and put four holes at equal distances, then insert two short dowels into the furthest holes.