Solution: The bisector of S=8 π =200.96 (square centimeter).
C=(8×2)×π=50.24 (cm)
There is a round flower bed in Xingguang Primary School. The perimeter of the flower bed is 25. 12m. What is the floor area of this flower bed? ×××
Solution: r = 25. 12 \u 2 = 4(m)
The square of s = 4×π = 50.24 (m2)
3. How many times can a copper wire with a length of 1570 be wound around a circular coil with a radius of 2.5cm?
Solution: 1570(2.5×2×π)
= 1570÷ 15.7
= 100 (circle)
4. Cut the disc with a rectangular iron sheet with a length of 10 cm and a width of 6 cm. The radius of the disc is 1.5 cm. How many can I cut at most?
Solution: 6÷( 1.5×2)=2.
10( 1.5×2)≈3 (approximate value of tail cutting method)
2×3=6
A: You can cut up to 6 pieces.
The echo wall of Beijing Tiantan Park is a world-famous acoustic miracle, and it is a circular wall. The perimeter of the fence is about 204.7 meters. What is its diameter and area respectively? (The number shall be kept to one decimal place)
6. Build a road with a width of 1 meter outside the circular flower bed with a diameter of 8 meters. How much floor tile area does it take to lay the path?
Solution: 8÷2=4 4+ 1=5.
(5 squared -4 squared) ×π=9×π=28.26
7. The wheel radius of a car is 0.3m Can this wheel cross a bridge with a length of 1800m after rolling for 1000 cycles?
(0.3×2)×π= 1.884 (m)
1.884×1000 =1884 (m)
Because 1884 > 1800
So I crossed a bridge with a length of 1800 meters.
1. What do graduate students (economics) study?
School is still very important, and economics is very popular now. If you go to graduate school, you will