Indlela yokufumana kujikelezo nxantathu?

Indlela yokufumana kujikelezo nxantathu? Ngoko ke umbuzo wabuzwa ngamnye kuthi, esikolweni. Makhe zama ukukhumbula yonke into esiyaziyo eli nani emangalisayo, kwakunye ukuba uphendule umbuzo.

Impendulo yalo mbuzo ka yokufumana indlela kujikelezo kanxantathu idla ilula - kuthatha nje-nje alandele inkqubo ye ukongeza ubude onke macala ayo. Noko ke, kukho izinto ezimbalwa iindlela ezilula ingakanani.

Tips

Xa kunjalo, ukuba radius (r) wesangqa ubhalwe unxantathu, yaye indawo yayo (S) baziwa, impendulo yombuzo yokufumana indlela kujikelezo kanxantathu nto ibonakala ngcono. Ukuze wenze oku, kufuneka ukuba usebenzise indlela eqhelekileyo:

P = 2s / r

Ukuba baziwa engile ezimbini, umzekelo, α kunye β, ezikufutshane kwicala ngokwayo kunye nobude icala, iiperimeter inokufumaneka usebenzisa ifomula kakhulu, zithandwa kakhulu oko kukuthi:

sinβ ∙ i / (nesono (180 ° - β - α)) + sinα ∙ i / (nesono (180 ° - β - α)) + a

Ukuba uyazi ubude macala ezikufuphi kunye β ekujikeni, apho phakathi kwabo, ukuze ufumane umjikelezo, kufuneka ukuba usebenzise indlela theorem of cosines. Lokubiyela ibalwa ngolu hlobo lulandelayo:

P = b + a + √ (B2 + A2 - 2 ∙ b ∙ kwaye ∙ cosβ),

apho A2 kunye B2 na wezikweri ubude macala ezikufutshane. ibinzana olukhulu - ubude lesithathu ayaziwa, ziphawulwe ngokuthi theorem cosine.

Ukuba awuyazi ukufumana indlela iperimitha ye unxantathu isosceles, apha, enyanisweni, akukho nto ibitheni ngotywala. Bala usebenzisa ifomula:

P = b + 2a,

apho b - isiseko unxantathu, yaye - namacala aso.

Ukuze ufumane kujikelezo unxantathu alinganayo kufuneka usebenzise indlela yokubala elula:

R = 3a,

nalapho - ubude icala.

Indlela yokufumana kujikelezo nxantathu ukuba siyazi kuphela radii le izangqa ezichazwe ngayo okanye wangena kuyo? Ukuba unxantathu na alinganayo, ngoko ke kufuneka sisebenzise ifomula:

P = 3R√3 = 6r√3,

apho R kunye r zizinto radii wesangqa nezisekelwe kwaye sibhalwe ngokulandelelanayo.

Ukuba unxantathu na isosceles, ngoko ifomula lisebenza kuye:

P = 2R (sinβ + 2sinα),

apho α - le angle edulusele esisekweni, kunye β --engile ekhangelene kwi siseko.

Amaxesha amaninzi, ukusombulula iingxaki zezibalo zifuna uhlalutyo olunzulu kunye nokukwazi ethile ukufumana ukubonisa neefomula afunekayo, njengoko abaninzi sazi, kakhulu umsebenzi onzima. Nangona ezinye iingxaki ingasombululwa nje indlela enye.

Makhe sihlolisise izinto ifomula ukuba isiseko ukuphendula umbuzo yokufumana indlela kujikelezo unxantathu, malunga ngasezantsi.Intlobo ngeentlobo zendidi koonxantathu.

Kakade ke, ulawulo ingundoqo ngokufumana kujikelezo nxantathu - le ngxelo: ke kufuneka ukuba abeke phantsi ubude macala kwi indlela efanelekileyo ekufumaneni kujikelezo unxantathu:

P = b + a + c,

apho b, yaye - ubude macala unxantathu, kunye P - kujikelezo nxantathu.

Kukho iimeko ezininzi ezizodwa ifomula. Masithi ingxaki yakho uqulunqe ngolu hlobo lulandelayo: "yokufumana indlela kwibala unxantathu ekunene" Kulo mzekelo, kufuneka usebenzise le ndlela ilandelayo:

P = b + a + √ (B2 + A2)

Kule formula, a kunye b ke ubude imilenze unxantathu ngokukhawuleza ekunene. Easy ukuqashela ukuba endaweni icala (hypotenuse) kusetyenziswa intetho yi theorem le sisazinzulu midala - kaPythagoras.

Ukuba ufuna ukusombulula ingxaki, apho oonxantathu efanayo, ngoko bekuya kuba sengqiqweni ukusebenzisa le ngxelo: umlinganiselo iiperimeters ngumlingani ahambelanayo kufana. Masithi ukuba oonxantathu ezimbini efanayo - ΔABC kunye ΔA1B1C1. Ke ukuba ufumane into lifane kwahlulwa kwi iiperimeter ΔABC ΔA1B1C1 ongaphandle kwebala.

Xa ndiqukumbela, kufanele kuphawulwe ukuba ingafunyanwa kujikelezo unxantathu besebenzisa iintlobo ngeentlobo zobuchule, kuxhomekeke idatha engumthombo ukuba unayo. Kufuneka kongezelelwa ukuba kukho ezinye iimeko ezizodwa ukuba oonxantathu ilungelo-engile egqithe.