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How to do these math problems? Urgent! ! ! ! ! ! ! ! !
This is an additional question for the final quality spot check of grade six in Yangpu District, Shanghai on 20 10.

It should be noted that at each vertex of the triangle, the circle does not roll, but the center moves on an arc.

The center of 1 should be 4 * 3 π r+2 π r =14 π r.

So twice is 28 π r.

The second one is more complicated.

Because the circumference of a circle is 2πr, the circumference of a triangle is 12πr, and the circle and triangle do not slide and roll, the distance traveled by the circle when it returns to its original position for the first time is 12πr = 6 times.

20 10/ 14 = 143。 . . . eight

So the center of the circle must bypass the triangle 143, and then take 8 π r. It took 3.5 turns to calculate this 8 π r.

Is the answer 86 1.5 laps?