Indlela yokufumana le achazwe apha

Umgca evaliweyo ukuba yahlula moya ibe ngamaqela amabini ekupheleni (ngaphakathi - isangqa) kunye akupheli (umgca ngaphandle), ukuba iye iipropati eziliqela ezithile, kuthiwa sisangqa. Umzekelo, ukuba kufuneka ukuthotyelwa equidistance lwamanqaku elele kulo mgca, ukususela kwindawo enye embindini wesangqa. Kuba moya buchazwa yi kwisangqa, kukho ezinye iimpawu oluninzi. Ezi ziquka:

• radius (umgama ukusuka naninina ulele kulo, kwiziko, r);
• ububanzi (umgca ngokwahlula isangqa ibe ngamaqela amabini alinganayo, bedlula ngamanqaku amabini kunye neziko isangqa wesangqa, d);
• indawo ngamanani ebonisa ubungakanani kwisangqa, S;
• ubude kumgca evaliweyo ukuba ichaza isangqa (otyunjwe yi unobumba Ḻ).

Ngenxa yoko, Ḻ ayikho nje iimpawu ubungakanani kwisangqa, kodwa umgca evaliweyo, ngoko ke impendulo yombuzo - bafunde njani na achazwe apha, iza kusebenza magama kwijometri.

Lisweleke Umgama yi into moya lwangaphandle ivaliwe curve imilo ngeenxa ilingana ubude kumgca zilurhangqile. Olu uvavanyo ubungakanani achazwe apha isetyenziswa umlinganiselo izinto eziphathekayo, kodwa xa ucinga iimilo nezinto zejiyometri. Eli gama linentsingiselo ekhethekileyo ulwazi zejometri kunye netrigonometri. It libhekisela ubuninzi emzimbeni, nto leyo ityala eyodwa into efana ongaphandle kwebala. NgesiGrike, igama izandi «περίμετρον» ( «isangqa») okanye «περιμετρέο» ( «umlinganiselo macala"). Umjikelezo (figure moya nayiphi na imilo) kunye achazwe apha (imilo ejikelezayo shape Planar) lilingana ubude lilonke iimilo kumda. Eyonanto ibalulekileyo (kumda wesangqa) unalo umlinganiselo efanayo umgama okanye indlela. Ukufunda isihloko "Indlela ukubala ubude wesangqa", kuyimfuneko ukuba ukukhumbula iiyunithi kunye translation zabo.

Ngokutsho ngamazwe kwinkqubo ka SI, nayiphi na indlela okanye umgama ulinganiswa eemitha. Le yunithi esisiseko, kodwa kukwakho yezabelo. Ngoko ke kufanelekile ukuba abo isigqibo kwiingxaki ithiyori kwaye aluncedo "ukuze ufumane indlela ubude achazwe apha le" kukhokelela ubuhlobo babo:

• 1 ngekhilomitha = 1000 eemitha = 10000 = 100000 decimeters iisentimitha = 1000000 ngemilimitha;
• 1 imayili = 1,609344 kweekhilomitha = 1609,344 16093,44 eemitha decimeters = = = 160,934.4 sentimitha milimitha 1.609.344;
• 1 ft = 30,48 iisentimitha = 304,8 eemilimitha decimeters = 3,048 = 0,3048 = 0,0003048 iimitha km.

Kukho nezinye iiyunithi ezininzi zomlinganiselo: i-British (okanye American), endala Russian, isiGrike, Japanese kunye nabanye. Ukuze bakwazi ukwenza izibalo, kucetyiswa ukuba usebenzise ulwazi yangasemva.

Ngokuba zonke izangqa luphawulwa into enye efanayo, eyasekwa zizazinzulu yamhlamnene. Umlinganiselo Ubude ukuya sangqa kwisangqa kusoloko inani rhoqo. Kangangexesha elide izazinzulu usebenzisa iindlela ezahlukeneyo (Samthi software ezizodwa kunye nobuchwepheshe computer), bazama ukumisela ixabiso ngqo loo nombolo. Oku kudla zibonakaliswe yileta lesiGrike «π» (libizwa ngokuba upi). Ixabiso sentengo ngamaxesha ahlukeneyo kwatshintsha, kodwa wayesoloko kancinane ngaphezu kwemithathu. Le π inani dimensionless. Namhlanje, oosonzululwazi baye bakwazi ukumisela emva kwesishumi ezilishumi ezigidi amanqaku. Le ukuchana kuyimfuneko ukuba izibalo ezintsonkothileyo lwezibalo. Kodwa ekucombululeni iingxaki zejiyometri, apho kuyimfuneko ukuba baphendule umbuzo - njani ukufumana achazwe apha, ngokuya usebenzisa le nombolo ukuya abalinganiswa ezintlanu okanye ezimbini: π ≈ 3,14159 ≈ 3,14.

Yinto eyaziwayo ukuba Ḻ / D = π = 3,14 okanye Ḻ / 2 r = π = 3,14. Ngoko kulula ukuphendula umbuzo - ukufumana indlela ubude la manani achazwe ye oyi kwimitha 1 okanye 2 decimeter, okanye ubudeki kangange-5. Kwane- banda kabini embindini okanye ububanzi we π inani. Ngokuba zonke zontathu iimeko kwifomula Ḻ = π • D = 3,14 • D okanye Ḻ = 2 • π • r = 2 • 3,14 • Ukukhumbula iziphumo ezifunyenweyo izibalo zilandelayo:

1. Ḻ = 3.14 • 2 • 1 = 6.28 m;
2. Ḻ = 3.14 • 2 • 2 DM = 12,56;
3. Ḻ = 3,14 • 5 = 15.7 cm.

Umsebenzi equlathe umbuzo - ukufumana indlela ubude achazwe apha, ukuba uyaziwa, radius okanye ubukhulu, kodwa indawo ezaziwayo isangqa, inzima kancinci, kodwa kwakhona kusombululeka. Ukuze ixesha elide kwakusazeka ukuba indawo setyhula elingana nemveliso π kunye isikweri radius okanye sangqa omnye sesine isikwere: S = π • ṟ² okanye S = π • D ² / 4.

Ukubala okwi yokuqala R = √ (S / π) okanye ubukhulu D = √ (4 • S / π), kwaye ke ubude circumferential ubalwe. Unako ukubona umzekelo iimeko ezimbini apho indawo isangqa ilingana 12,56 m² kunye 78,5 cm²:

1. R = √ (12,56 / 3,14) = 2 m, kanti Ḻ = 3.14 • 2 • 2 = 12.56 m okanye D = √ (4 • 12,56 / 3,14) = 4 m, ngoko Ḻ = 3,14 • 4 = 12.56 m.
2. R = √ (78,5 / 3,14) = 5 cm, ngoko Ḻ = 3.14 • 5 • 2 = 31.4 cm okanye D = √ (4 • 78.5 / 3.14) = 10 cm ngoko Ḻ = 3,14 • 10 = 31.4 cm.