Answer: 21 minutes
Step-by-step explanation: A complete revolution has 360°. The tower rotates completely after 60 minutes, which means:
360° - 60 min
The restaurant rotated 126° while the visitor was at the tower, so using proportionality rule:
360° - 60 min
126° - t min
[tex]t=\frac{126*60}{360}[/tex]
[tex]t=\frac{126}{6}[/tex]
t = 21
The visitor was at the tower for 21 minutes.