What has 3 feet but no toes?

“A ruler”

While a ruler measures length, it typically measures in inches or centimeters rather than feet.

“A measuring tape”

A measuring tape can measure in feet, but it does not have a fixed length of 3 feet like a yardstick does.

“A tripod”

A tripod has three legs (often referred to as feet), but it is used for stability rather than measuring length.