Indlela yokufumana ukuphakama trapezoid?

Xa ubomi bethu rhoqo kufuneka ukujongana nokusetyenziswa geometry e practice, ezifana zokwakha. Phakathi iimilo zixhaphakileyo zejiyometri, kukho neemvumi. Nokuqinisekisa ukuba iprojekthi yimpumelelo yaye intle, kufuneka ubalo olufanelekileyo noluchanekileyo ye iziqalelo ze ngokomzekeliso enjalo.

Yintoni a yegumbi? Le Ikwadrilatherali khaxa ene iperi macala ngaxeshanye, ochazwa ngokuba kwisiseko trapezoid. Kodwa kukho ezinye iinkalo ezimbini ukudibanisa ezi zizathu. Loo maKristu abizwa ngokuba lateral. Enye imiba ephathelele kulo mzobo, oko kukuthi: "Indlela yokufumana kubude trapezoid" Kufuneka nje ukunikela ingqalelo ukuphakama - icandelo egqiba umgama ukusuka kwisiseko ukuya kwenye. Kukho iindlela ezininzi ukujonga lo mgama, ngokuxhomekeka phezu variables ezaziwayo.

1. izixa Ezaziwayo zombini iziseko, b ukonakala yaye k, kwakunye ndawo trapezoid. Ukusebenzisa amaxabiso eyaziwa ukufumana kubude trapezoid, kule meko ngokulula kakhulu. Njengoko yaziwa ukusuka geometry, indawo trapezoid zibalwe imveliso yesiqingatha isixa kwesiseko nokuphakama. Ukusuka kule formula kube lula kuveliswe ixabiso olifunayo. Ukuze wenze oku, yahlula indawo isiqingatha semali kwamabala. Kwifomula kungaba ngolu hlobo:

S = ((b + k) / 2) * h, apha h = S / ((b + k) / 2) = 2 * S / (b + k)

2. Iyaziwa ubude osembindini, siya ukubonisa d, kunye isikwere. Kuba abo bangamaziyo, umgca eliphakathi umgama phakathi iincam emacaleni. Indlela yokufumana kubude trapezoid kule meko? Ngokutsho trapezoid ipropati, umgca embindini ingqamana isiqingatha isixa zeenqwelwana, ngamanye d = (b + k) / 2. Kwakhona siya babhenele square olungumgubo. Ukutshintshwa isiqingatha semali engange-kumzantsi ixabiso umgca ophakathi, sinokuyifumana kulandelayo:

S = d * h

Njengoko kubonakala kwifomula wafumana ukuphakama kwakuthe ngokulula kakhulu. Lidala indawo kwi osembindini yexabiso, siya kufumana inani elingaziwayo. Sibhala le ifomula:

h = S / d

3. Ukwazisa ubude elinye icala (b) kunye angela phakathi nangapha noseko inkulu. Impendulo yalo mbuzo ka yokufumana indlela ukuphakama trapezoid, nayo kule meko. Cinga ABCD trapezoid, apho AB kunye CD ke amacala osecaleni, apho AB = b. Isiseko kunazo AD. Le angela yi AB kunye AD luchazwa α. Ukusuka kwindawo B ayishiyelele h ukuphakama phezu kwesiseko AD. Ngoku cinga unxantathu onesiphumo ABF, nto leyo buxande. Side AB lo hypotenuse, kunye BF-emlenzeni. Ukusuka impahla triangle ekunene ixabiso ratio cathetus kunye hypotenuse ekwafanekisa ixabiso i sine ye-engile le cathetus malungana (BF). Ngoko ke, ingqalelo oku kulapha ngentla, ukubala ubude trapezoid phinda ixabiso nomba othile kunye sine-angle α. Xa ifomula oku ngolu hlobo lulandelayo:

h = b * isono (α)

4. Ngokufanayo, ukuba ngaba ubukhulu eyaziwayo ecaleni kunye engile zibonakaliswe β, kwakheka phakathi nangapha noseko ezincinane. Ekusombululeni ingxaki enjalo, engile phakathi icala kubude eyaziwa neyaziwa 90 ° - β. Ukususela iimpawu triangles - ratio ubude cathetus kunye hypotenuse ekwafanekisa i cosine ye-engile phakathi kwabo. Ukusuka kule formula kulula baphethe ixabiso ubude:

h = b * cos (β-90 °)

5. Indlela yokufumana kubude trapezoid, ukuba uyaziwa kuphela embindini wesangqa sibhalwe? Ukususela kwenkcazo kwisangqa, kumayelana enye ingongoma kwisiseko ngasinye. Ukongeza, ezi ngongoma elungelelaniswe embindini wesangqa. Kulo kulandela ukuba umgama phakathi kwabo na ububanzi, yaye kwangaxeshanye, ukuphakama trapezoid. Kubonakala ngathi le nto:

h = 2 * r

6. Ngokufuthi kukho imisebenzi ekufuneka ukufumana ubude i trapezoid isosceles. Khumbula ukuba trapezoid zinamacala alinganayo kuthiwa i isosceles. Indlela yokufumana ubude isosceles trapezoid? Ukuba idayagonali kukho ukuphakama nkqo ilingana isiqingatha isixa zeenqwelwana.

Kodwa yintoni ukwenza ukuba ezi idayagonali hayi aa Incopho na? Cinga trapezoid ABCD isosceles. Ngokweempawu zayo, neziseko zibe ngaxeshanye. Kulo kulandela ukuba engile kwi kwisiseko iya kulingana. Zoba eziphakamileyo ezimbini BF kunye CM. Ngokusekelwe kule nkcazelo ingasentla, oko Kungaphikiswa ukuba oonxantathu ABF kunye DCM bayalingana, oko kukuthi, AF = DM = (AD - BC) / 2 = (bk) / 2. Ngoku, kusekelwe phezu kweemeko ingxaki, ukuchaza ubungakanani aziwayo, uze ufumane kwendawo, kuthathelwa ingqalelo zonke iipropati ye trapezoid isosceles.