确定起跑线 (9)

1、确定起跑线人教版六年级数学上册132终点线确定起跑线 (9)85.96m72.6m第六道直径：周长：全长：85.1m267.35m439.27m第七道直径：周长：全长：85.11.251.25=87.6（m）87.63.14159275.20（m）85.962275.2=447.12（m）72.6228.0840075.1235.93407.8577.6243.79415.7180.1251.64423.5682.6259.5431.4285.1267.35439.2787.6275.2447.1290.1283.06454.98注：取3.14159各跑道的起跑线应该相差多少米？7.85m/

2、7.86m7.857.867.857.867.857.857.8685.96m72.6m第六道直径：周长：全长：85.1m267.35m439.27m第七道直径：周长：全长：85.11.251.25=87.6（m）87.63.14159275.20（m）85.962275.2=447.12（m）85.96m72.6m第五道直径：周长：全长：82.6m259.5m431.42m第六道直径：周长：全长：82.61.251.25=85.1（m）85.13.14159267.35（m）85.962267.35=439.27（m）72.6228.0840075.1235.93407.8577.6243.

3、79415.7180.1251.64423.5682.6259.5431.4285.1267.35439.2787.6275.2447.12注：取3.1415972.6228.0840075.1235.93407.8577.6243.79415.7180.1251.64423.5682.6259.5431.4285.1267.35439.2787.6275.2447.12注：取3.1415985.96m72.6m1.25m1.25m1.25m85.96m72.6m1.25m1.25m1.25m注：取3.1415985.96m72.6m第一道直径：周长：全长：72.6m72.63.1415922

4、8.08（m）85.962228.08=400（m）72.6228.08400注：取3.1415985.96m72.6m第一道直径：周长：全长：72.6m228.08m400m第二道直径：周长：全长：72.61.251.25=75.1（m）75.13.14159235.93（m）85.962235.93=407.85（m）1.25m1.25m72.6228.0840075.1235.93407.85注：取3.1415985.96m72.6m第二道直径：周长：全长：75.1m235.93m407.85m第三道直径：周长：全长：75.11.251.25=77.6（m）77.63.14159243.

5、79（m）85.962243.79=415.71（m）1.25m1.25m75.1m72.6228.0840075.1235.93407.8577.6243.79415.71注：取3.1415985.96m72.6m第三道直径：周长：全长：77.6m243.79m415.71m第四道直径：周长：全长：77.61.251.25=80.1（m）80.13.14159251.64（m）85.962251.64=423.56（m）1.25m1.25m77.6m72.6228.0840075.1235.93407.8577.6243.79415.7180.1251.64423.56注：取3.141598

6、5.96m72.6m第四道直径：周长：全长：80.1m251.64m423.56m第五道直径：周长：全长：80.11.251.25=82.6（m）82.63.14159259.50（m）85.962259.5=431.42（m）确定起跑线 (9)72.6228.0840075.1235.93407.8577.6243.79415.7180.1251.64423.5682.6259.5431.42注：取3.1415985.96m72.6m第五道直径：周长：全长：82.6m259.5m431.42m第六道直径：周长：全长：82.61.251.25=85.1（m）85.13.14159267.35（

7、m）85.962267.35=439.27（m）确定起跑线 (9)72.6228.0840075.1235.93407.8577.6243.79415.7180.1251.64423.5682.6259.5431.4285.1267.35439.27注：取3.1415985.96m72.6m第六道直径：周长：全长：85.1m267.35m439.27m第七道直径：周长：全长：85.11.251.25=87.6（m）87.63.14159275.20（m）85.962275.2=447.12（m）72.6228.0840075.1235.93407.8577.6243.79415.7180.12

8、51.64423.5682.6259.5431.4285.1267.35439.2787.6275.2447.12注：取3.1415985.96m72.6m第七道直径：周长：全长：87.6m275.2m447.12m第八道直径：周长：全长：87.61.251.25=90.1（m）90.13.14159283.06（m）85.962283.06=454.98（m）72.6228.0840075.1235.93407.8577.6243.79415.7180.1251.64423.5682.6259.5431.4285.1267.35439.2787.6275.2447.1290.1283.064

9、54.98注：取3.14159各跑道的起跑线应该相差多少米？7.85m/ 7.86m7.857.867.857.867.857.857.8672.6228.0840075.1235.93407.8577.6243.79415.7180.1251.64423.5682.6259.5431.4285.1267.35439.2787.6275.2447.1290.1283.06454.98注：取3.14159我不用算出每条跑道的长度，也知道它们相差多少米?两条直道是一样的，所以只需要看圆的周长。圆的周长是这样算的：第一道：72.6第二道：(72.62.5) = 72.62.5第三道：(75.12.5) = 75.12.5第四道：(77.62.5) = 77.62.5第五道：(80.12.5) = 80.12.5第六道：(82.62.5) = 82.62.5第七道：(85.12.5) = 85.12.5第八道：(87.62.5) = 87.62.5每一条跑道都在上一条跑道的基础上增加2.5的长度。你能算出2.5是多少米吗？终点起点200米的跑道，每条道的长度都是它们全长的一半。第一条：4002=200（m）第二条：407.852=