A tower has a revolving restaurant 840 feet above the ground. The restaurant makes a complete revolution every 60 minutes. While a visitor was at the tower, the restaurant rotated through 126°. How long was the visitor at the tower? The visitor was at the tower for minutes.

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

t = 21

The visitor was at the tower for 21 minutes.