问题1人教版六年级上册第65页第5题:一个圆形牛栏的半径是15m,要用多长的粗铁丝才能把牛栏围上3圈?(接头处忽略不计.)如果每隔2m.栽一根木桩,大约要栽多少根木桩?解(1)2×3.14×15×3=282.6(m),答:要用282.6m长的粗铁丝才能把牛栏围上3圈.(2)2×3.14×15=94.2(m),94.2÷2=47.1≈47(段).在题中隐含着木桩所占的空间忽略不计,因为 Question 1 PEP 6th grade Volume 65, Number 5 Question 5: The radius of a circular bullpen is 15m, how long is the length of wire used to enclose the bullseye for three turns? (The joints are ignored.) If each Answer 2 (1) 2 × 3.14 × 15 × 3 = 282.6 (m), A: The use of 282.6m long thick wire can be placed around the bullpen three laps (2) 2 × 3.14 × 15 = 94.2 (m), 94.2 ÷ 2 = 47.1 ≈ 47 (paragraph). The space implied by the stake in the title is negligible because