Question 1: Path area = the area of the paved circle around the flower bed-the area of the original flower bed, where the radius of the paved circle is 10/2+2=7 meters, then the path area =7? π-5? π=24π square meters

The second question: The reason for this question is the same as the first question. This question tells us the diameter of the big circle and requires us to dig a small circle and leave a 6-meter-wide circular road surface. Then the diameter of the small circle dug out is 40-2 * 6 = 28, and then the area of the road surface comes out. Keep this for yourself.

Question 3: How to calculate the width of the ring? If you don't know, you can draw a schematic diagram on the draft paper. The width of the circle = the radius of the outer circle-the radius of the inner circle or the width of the circle = (the diameter of the outer circle-the diameter of the inner circle) /2, then the circumference of the circle is known in the stem. According to the circumference formula, the circumference =2πr(r is the radius) to calculate the circle radius and get the answer.

Question 4: The distance traveled by the tip in one minute is equivalent to finding the perimeter, then 45 minutes is equivalent to walking 45/60=3/4 circles, then the perimeter of a circle =2*20π=40π, then how many are three-quarters circles? I believe you will.

Question 5: The previous question of this question is the same as the previous one. It takes 12 hours for an hour hand to walk once a day, so it takes two times a day to calculate the length and area of a circle. Multiplying those two laps by two should be correct.

Question 6: This question tells you the circumference of a circle and asks you to find the area of the circle. According to the circumference =2πr and the radius r = l/2π =1.57/(2 * 3.14) = 0.25, then the area of the circle S=πr? =3. 14*0.25? =0. 19625 square meters, leaving two decimal places is 0.20 square meters.

Finally, I want to tell you that these questions are all about the operation of a circle. In fact, there are only two formulas for the operation of a circle: perimeter L=2πr and area S=πr? . As long as these two formulas are used to find the radius r, then other problems are solved. When you can't figure it out, just draw a picture on the draft paper. When you are not afraid of math, think more and practice more, then your math scores will improve!