Kugara nePentagon: shoma ruzivo

Rinotsanangura Dictionary Ozhegova rinoti kuti nePentagon ari geometric mufananidzo, achingopiwa shanu intersecting mitsetse anoumba shanu dzakawanda dzinoita, uyewo chero chinhu zvakafanana chimiro. Kana zvose mativi uye pamakona zvakafanana pamamiriro polygon, kunonzi kodzero (nePentagon).

Chii chinonakidza dzose nePentagon?

Rakanga chimiro ichi kwave zvakavakwa pamusoro yakakurumbira pakuvaka United States Defence. Of bhuku dzose polyhedrons chete dodecahedron ane pamucheto muchimiro nePentagon. Zvakasikwa hapana crystals zvachose, inobudisawo izvo zvingadai takafanana nguva nePentagon. Uyezve, mufananidzo uyu polygon pamwe risingamboshandisi nhamba pamakona, izvo hazvibviri Tile munharaunda. Chete kwenhamba diagonals pakati nePentagon anoenderana nenhamba kumativi acho. Bvumiranai, izvi zvinonakidza!

Basic zvivako uye nzira

Uchishandisa zvokuimba chipi dzose polygon, unogona kutsanangura zvakakodzera zvose parameters ari, unova nePentagon.

• The nechepakati angled α = 360 / n = 360/5 = 72 °.
• Yomukati angled β = 180 ° * (n-2) / n = 180 ° * 3/5 = 108 °. Saizvozvowo, Verengai menyika pamakona ndiyo 540 °.
• Nhamba yacho diagonal kune lateral divi akaenzana (1 + √5) / 2, i.e. ari "yendarama chikamu" (vanenge 1,618).
• Kureba parutivi, iro rine dzose nePentagon kunogona vakaverenga nomumwe matatu Masvomhu, zvichienderana iyo parameter zvapera anozivikanwa:

• kana rinotsanangura denderedzwa kunhivi inozivikanwa uye nharaunda R, ipapo munhu = 2 * R * chivi (α / 2) = 2 * R * chivi (72 ° / 2) ≈1,1756 * R;
• apo munenge denderedzwa nharaunda R nokudhindwa dzose nePentagon, a = 2 * R * nkm (α / 2) = 2 * R * nkm (α / 2) ≈ 1,453 * R;
• zvinoitika kuti panzvimbo kuvazivisa zvikuru radii diagonal D, ipapo mirayiridzo kunotemwa sezvinotevera: kuva ≈ D / 1,618.

• Nzvimbo dzose nePentagon atsunga, zvakare, zvichienderana iro parameter anozivikanwa kwatiri:
• kana pane rakanyorwa kana circumscribed denderedzwa, ipapo kushandisa rimwe Masvomhu maviri:

S = (n * imwe * R ) / 2 = 2,5 * imwe * R kana S = (n * R ² * chivi α) / 2 ≈ 2,3776 * R ^2;

• nharaunda rinogonawo tsunga nokuziva chete parutivi pakureba:

S = (5 * ² * tg54 °) / 4 ≈ 1,7205 * ^2.

Kugara nePentagon: chivakwa

Izvi geometric chimiro zvinogona kuvakwa nenzira dzakasiyana. Somuenzaniso, kuti aenderane ndokuita denderedzwa rine nharaunda akafanorongerwa inobva akafanorongerwa tinova divi. Kutevedzana rave inorondedzerwa "Zvinoumba" pamusoro Euclid kunhivi 300 BC Chero zvazvingava, tinofanira kuva kambasi uye mutongi. Funga kushandisa nzira rokuvaka akafanorongerwa sekamufarenzi.

1. Sarudza zvemasanga nharaunda, uye tara denderedzwa, kureva payo pfungwa O.

2. On denderedzwa mutsetse, sarudza pfungwa kuti richava rimwe shongwe pakati nePentagon wedu. Uyu pfungwa A. Connect pfungwa O uye A mutsetse chidimbu.

3. Tara mutsetse kubudikidza pfungwa perpendicular kuti twasu mutsetse OA. Isa mharadzano iyi yakarurama maererano denderedzwa chiratidzo sezvo pfungwa B.

4. Panguva pakati daro pakati pfungwa O uye B tinova pfungwa C.

5. Zvino kuzochera denderedzwa ane pakati iri panguva C uye ichipfuura pfungwa A. Chinzvimbo kuti mharadzano kwayo yakarurama mutsetse Ob (zvingava mukati wokutanga denderedzwa) ndiyo kunongedzera D.

6. avake denderedzwa kuburikidza D, muzinda riri Area A pakati mharadzano dzaro chepakutanga denderedzwa zvinokosha kuziva pfungwa E uye F.

7. Zvino kuvaka denderedzwa ane centre iri E. Kuita izvi zvakafanira kuitira kuti ichipfuura A. Zviri imwe nzvimbo mharadzano chepakutanga denderedzwa kunokosha ratidzai pfungwa G.

8. Pakupedzisira, avake denderedzwa rine muzinda A kuburikidza pfungwa F. Mark mumwe mharadzano pfungwa yepakutanga denderedzwa H.

9. Zvino iwe chete vane kubatanidza pamusoro A, E, G, H, F. Our dzose nePentagon takagadzirira!