The minute hand of the big clock on the roof of the hotel is 0.6 meters long, so how many decimeters did the needle tip of the minute hand walk from noon 12 to 3 pm?

The original radius is188.4/3.14/2 = 30 (m).

The original radius is 30+ 1=3 1 (m).

The original area is 3. 14*30*30=2826 (square meter).

The original area is 3.14 * 31* 31= 3017.54 (square meter).

The widened area is larger than the original;

3017.54-2826 =191.54 (m2)

2)

The minute hand walked 60*3= 180 laps from noon to 3 pm.

The minute hand leaves from noon 12 to 3 pm.

2 * 3.14 * 0.6 *180 = 678.24 (m)