How kuwana sekamufarenzi

A up mutsetse runoparadzanisa ndege muzvikamu zviviri magumo (mukati - denderedzwa) uye haaperi (kunze mutsetse), chero bedzi kuti ane chaizvo ehupfumi wandei, inonzi denderedzwa. Somuenzaniso, zvaida abvume equidistance pfungwa avete mutsetse uyu, kubvira imwe nguva ari pakati denderedzwa. Nokuti ndege kunorondedzerwa denderedzwa, pane zvimwe zvinoratidza quantitative. Idzi dzinosanganisira:

• nharaunda (daro chero pfungwa avete pariri, kuti pakati, R);
• dhayamita (mutsetse kupatsanura denderedzwa munzvimbo mbiri dzakaenzana zvikamu, achipfuura mbiri pfungwa uye denderedzwa pakati denderedzwa, D);
• nzvimbo dziwande kuratidza kukura denderedzwa, S;
• Kureba namahwindo mutsetse anotsanangura denderedzwa (varehwa tsamba Ḻ).

Saka, Ḻ harisi chete quantitative cho denderedzwa, asi namahwindo mutsetse, saka mhinduro yomubvunzo - sei kudzidza kuti sekamufarenzi, rinoshanda kune vose geometrical pfungwa.

Daro wakamhanya nemunhu zvokunze chinhu ndege akavhara munyonga kumativi chimiro akaenzana pakureba mutsetse pakubhiti nayo. Izvi quantitative tinyatsonzwisisa kuti sekamufarenzi inoshandiswa nokuyerwa mumuviri midziyo, asiwo kana tichifunga husingaoneki geometric zvitarisiko. Izwi ane zvaanoreva geometric uye trigonometric ruzivo. Rinoreva kuti mumuviri uwandu, inova nyaya inokosha zvakadaro chinhu sechinhu mukomberedzo. MuchiGiriki, shoko rinonzwika «περίμετρον» ( «denderedzwa») kana «περιμετρέο» ( «chiyero kumativi"). Mukomberedzo (Ndege mufananidzo upi chimiro) uye sekamufarenzi (dzeraundi chimiro nokuti planar chimiro) vakaenzana zvachose pakureba muganhu zvitarisiko. Special nyaya (muganhu denderedzwa) ine divi sezvo kure kana nzira. Kudzidza nyaya "How kuverenga urefu denderedzwa", zvinokosha kuyeuka dzakabatana uye Vakashandura.

Maererano yemarudzi hurongwa SI, nzira ipi kana kure akayera mu mamita. Ndicho hweBazi, asi pane nomukaka. Saka zvakakodzera kuti vaya vanosarudza yokungotaura uye anoshanda matambudziko "sei kuwana nokureba sekamufarenzi ari" kutungamirira ukama hwavo:

• 1 kiromita = 1000 metres = 10000 = 100000 decimeters masendimita = 1000000 millimeters;
• 1 maira = 1,609344 makiromita = 1609,344 16093,44 metres decimeters = = = 160,934.4 masendimita millimeters 1.609.344;
• 1 Ft = 30,48 masendimita = 304,8 millimeters decimeters = 3,048 = 0,3048 = 0,0003048 mamita makiromita.

Kune dzimwe zviumbu zhinji yakayerwa: weBritish (kana American), akwegura Russian, Greek, Japanese uye nevamwe. Kuti ivo kuita Masvomhu, Zvinokurudzirwa kushandisa mashoko okuwedzera.

For madenderedzwa zvose dzinoratidzwa chimwe chinhu chakafanana, yakasimbiswa nemasayendisiti kare. Ratio urefu kuti dhayamita mumwe denderedzwa iri nguva dzose kugara nhamba. Kwenguva refu masayendisiti vachishandisa nzira dzakasiyana (uye pakarepo unyanzvi hwakasiyana-software uye kombiyuta michina), vari kuedza kumisa chaiyo kukosha nhamba iyoyo. Zvinonzi Kazhinji runotaurwa tsamba Greek «π» (iziviswe sezvo Pi). The anofungidzirwa ukoshi panguva dzakasiyana-siyana, asi pakanga nguva dzose zvishoma kupfuura vatatu. The nhamba π iri dimensionless. Nhasi, masayendisiti vakakwanisa kumisa mushure grade pfungwa mavanga gumi tiririyoni. Kururama Izvi zvakakodzera nokuti kunzwisisa masvomhu. Asi kugadzirisa matambudziko geometric, apo kunodiwa kupindura mubvunzo - sei kuwana sekamufarenzi, kuramba vachishandisa nhamba iyi kusvika mashanu kana mbiri kutaurwa: π ≈ 3,14159 ≈ 3,14.

Zvinozivikanwa kuti Ḻ / D = π = 3,14 kana Ḻ / 2 R = π = 3,14. Saka zviri nyore kupindura mubvunzo - sei kuwana pakureba kubva sekamufarenzi ane nharaunda 1 mita kana 2 decimeter, kana dhayamita 5 masendimita. Wakakwanisa Makawanza kaviri nharaunda kana dhayamita nhamba π. Nokuti zvose zvitatu nyaya kubudikidza nzira Ḻ = π • D = 3,14 • D kana Ḻ = 2 • π • R = 2 • 3,14 • R migumisiro vakawana Masvomhu zvinotevera:

1. Ḻ = 3.14 • 2 • 1 = 6.28 M;
2. Ḻ = 3.14 • 2 • 2 dm they = 12,56;
3. Ḻ = 3,14 • 5 = 15,7 cm.

Basa ane mubvunzo - sei kuwana kureba sekamufarenzi, kana kuzivikanwa, ayo nharaunda kana dhayamita, asi inozivikanwa kunharaunda denderedzwa, yakaoma zvishoma, asi rinogonawo kugadziriswa. Kwenguva refu zvinozivikanwa kuti raundi nzvimbo akaenzana zvibereko π uye yaiungana yacho nharaunda kana dhayamita mumwe chechina sikweya: S = π • ṟ² kana S = π • D ² / 4.

Pakuverenga nharaunda rokutanga R = √ (S / π) kana dhayamita D = √ (4 • S / π), uye ipapo akaverenga circumferential kureba. Unogona kuona muenzaniso panyaya mbiri apo nzvimbo denderedzwa akaenzana 12,56 m² uye 78,5 cm²:

1. R = √ (12,56 / 3,14) = 2 m, nepo Ḻ = 3.14 • 2 • 2 = 12.56 M kana D = √ (4 • 12,56 / 3,14) = 4 m, ipapo Ḻ = 3,14 • 4 = 12.56 m.
2. R = √ (78,5 / 3,14) = 5 cm ipapo Ḻ = 3.14 • 5 • 2 = 31.4 masendimita kana D = √ (4 • 78.5 / 3.14) = 10 masendimita ipapo Ḻ = 3,14 • 10 = 31.4 cm.