Hehe, this question is also a junior high school question, and it is an Olympic Games question in grade 5. The first small question: set the distance of 3 points x minutes, and then overlap. Then solve the equation (360/60) x = (360/12) x3+x/60x (360/12): x =180/1min. The second small problem: set the distance of 3 points x minutes and turn it into a right angle. Then solve the equation (360/60) x-180 = (360/12) x 3+x/60 x (360/12): x = 540/165438. The third small problem: set the distance of 3 points x minutes and turn it into a right angle (in the same way). Then solve the equation (360/60) x-90 = (360/12) x3+x/60× (360/12): x = 360/1min. Solve the problem, finish writing and call it a day!