It is the area of one large sector plus two small sectors. Large fan: the radius is 4m, the angle is 360-60=300 degrees, and the area is 4 times 4 times 3. 14 times 300 and then divided by 360, which equals 41.87m2; Small fan, radius 1m, angle 120 degrees, area 1 multiplied by 1, multiplied by 3. 14 multiplied by 240, divided by 360, equals 2.09, and the area that a dog can reach is 4/kloc-0. In fact, this is just a math problem, which is unrealistic, just like people answer, how old is the dog? Where the dog is tied by a rope, the area it can reach is different.

During the Cultural Revolution, a teacher asked the students a question: How far is it from Beijing to Guangzhou? The concerned students replied: All roads lead to Guangzhou, so why should the teacher insist? It's not far from beating around the bush, and students are worried if they don't ask strict questions