To determine which measurement has three significant digits, we can analyze the options provided:
- 134 meters - This has three significant digits (1, 3, and 4).
- 56.09 inches - This has four significant digits (5, 6, 0, and 9).
- 0.52 centimeters - This has two significant digits (5 and 2); the leading zero does not count.
- 8009 miles - This has four significant digits (8, 0, 0, and 9).
Based on this analysis, the measurement that has three significant digits is 134 meters.