ݷʱ : 2024/12/23 3:53:59һ µȫĶ
ڼܳõʲôλܾ˵𣿣סףףǧףĿ𣿣
2ſμ
ܾ˵ʲôƽͼε𣿣ıΧƽĴСǵ
õλЩƽסƽסƽף 3ƽͼεܳıȽϣ
⣺뾶Ϊ1cmԲܳ˵Ϊʲô 1ж1ж1cmжƱȻһ 2ܳļ㣺
1ѧļͼεܳ㹫ʽΪʲôҪ㣿
εܳĹʽ ĸʽ εܳĹʽ ĸʽ Բ֪ܳ뾶 ֱ֪
2ѧϰļͼε㹫ʽЩʽôƵģ
ϰſμ
1һƽıκһεȵȸߣ֪ƽıεδ7ƽסεǣ ƽıεǣ
2СԲ뾶2cmԲ뾶3cmСԲԲܳıǣ
3һԲֽƬƴһڰ뾶ȵĽƳΣε12.56 cmԭԲֽƬǣ cm
ġСڿЩջ 塢ҵ
ҵ87ҳġһ4⣬ϰʮ89ҳ5⣬91ҳ16⡣ κҵ87ҳġһ1⡢3⣬ϰʮ89ҳ23468⡣
21
22ѧ˼
˹оԡǻ۲DZģֻ֯úܺõ֪ʶϵϰεĿ֮һǽʦƽʱɢѧ֪ʶ㣬ѧһࡢϣŪǵȥ֪ͨʶ֮ϵһ֪ʶӶγõ֪ṹӽĽǶȿѧѧϰָѧԼѧ֪ʶĻˣϰҪѧһĿռ䣬ѧȥһԼ֪ʶһڡγõ֪ṹڡѧķ
ʱ ͼεʶ3
ѧݣʶͼΡ ѧĿ꣺
1ʹѧʶ塢壬ԲԲ֪ǵص㡣 2ѧϴӲͬ״
3ͼεʶֱ۹۲죬ʵѧϰ
4ǿѧ֪ʶճϵչѧĿռѧĴ¾ ѧصѵ㣺ͼ塢塢Բص㡣 ѧμ ѧ̣
һϰعˣͼεʶ һʶ
ٲſμ88ҳ4һͼ
ָѧ˵˵ͼεƺص㡣 ѧ˵һ˵ͼиĸʾʲô ܰͼη
ÿ涼ƽ һ
Բ Բ
ݳ
22
1ص㡣 ͬ 桢12⡢˸ ͬ ĸdzΡ 涼 2Ĺϵ壬ͼԣ ʶԲԲ
ԲԲʲôص㣿˵һ˵дһд
Բ棬棬ͬСԲһ档 Բ棬һԲһ档 ϰ
88ҳ489ҳ9ԲʲôͼתõԳεһΪתɣԲʲôͼתõģֱεһֱDZΪᣬתɡ Сڿʲôջ ġҵ 1 ͼ ƽı Բ ߳뾶 12m 20m ϵ7dmµ12dm ֱ ܳ 6m 9m 14m 9dm 22.4dm 25.12cm 78cm2
ѧ˼ 1עؼǿ֪ʶϵ
ڿΣץס㣺һǿռͼεγɣǿռͼε֪ʶҾ֪ͨʶɽѧߡڸϰռͼεγʱѧܵͼθԵͬԼͬ㣻ڸϰռͼε֪ʶʱͨ۲졢䡢ͼε֪ʶͨ飬֪ʶ磬ǿ֪ʶϵ 2עطչѧĿռ
ͨĽѧߣѧͼεʶּڶСѧѧ
23
ͼνǿϵʵؿѧ֪档磺ѧԲIJչһʱ˳ѧһdzмֿܣչȽϣڱȽϱѧ֪ṹչռ
4ʱ ͼεʶ4
ѧݣͼεʶͼεıļ㡣 ѧĿ꣺
1ϰ塢塢ԲԲļ㹫ʽѧͼεʶʹѧѧ֪ʶϵͳ 2ͨʵʲѧĶֲ
3ʹѧڽʵĹУѧϵ ѧصѵ㣺
1ɸͼεı㹫ʽϵ 2ѧ֪ʶеʵ⡣ ѧμ ѧ̣
һϰļ㣺 1Ķ壺
ʲôͼεı塢塢ԲıЩ֣
ڳıЩ֮ͣԲıЩ֮ͣ 2ϰԲIJ
ԲIJظչʲô״չijεijԲʲôϵԲIJ㣿
չijεijԲĵܳԲĸߡ ԲIJ=ܳ S=ch
3DZļ㷽88ҳıУдͼεı㹫ʽ S=2ab+ah+bh
S=6a
SԲ=2rh+2r
ͼε㹫ʽ
1ϰ壬壬ԲԲ
һװˮУ㿴ʲô ˮˣΪռԲˮĿռ䡣
Ȥһλΰѧң£һɣӶĴš
2ϰ壬壬ԲԲ㷽 S
V= a b h V=sh
24
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