Mene ne da'irar matsayin geometrical adadi: na asali dũkiyarsu da kuma halaye

Don fayyace su yi tunanin cewa irin wannan da'irar, dubi zobe ko hoop. Zaka kuma iya daukar wani zagaye gilashi tasa da kuma sa juye a kan wani takarda da fensir don da'irar. Lokacin da wani mahara karuwa a sakamakon line zai zama da kauri da kuma ba sosai santsi, kuma ta gefuna ne Heart. Karkara a matsayin na lissafi adadi yana da irin wannan fasali a matsayin kauri.

Karkara: definition da kuma bayanin irin na asali wajen

Karkara - rufaffiyar kwana kunshi wani jam'i na da maki located in daya jirgin sama da kuma equidistant daga cibiyar daga cikin da'irar. Duk da haka, da cibiyar ne a cikin wannan jirgin sama. Kamar yadda mai mulkin, shi ne denoted da wasika O.

A nesa daga wani batu na cikin karkara zuwa cibiyar da ake kira radius da kuma nuna ta harafi R.

Idan ka gama da wani maki biyu daga cikin da'irar, sa'an nan sakamakon rabi da aka kira wani tsirkiya. A tsirkiya wucewa ta cikin cibiyar daga cikin da'irar, - diamita wakilta harafi D. A diamita da rababben karkara a cikin biyu daidai arcs da tsawon sau biyu yake da radius daga cikin ƙuduri. Saboda haka, D = 2R, ko R = D / 2.

Properties guitar

1. Idan wani maki biyu daga cikin karkara rike da tsirkiya, sa'an nan perpendicularly zuwa karshen - radius ko diamita, wannan sashi zai karya da tsirkiya, kuma baka warware shi cikin biyu daidai sassa. Gãnãwa, kuma gaskiya ne: idan radius (diamita) na tsirkiya ya raba a cikin rabin, to, shi ne perpendicular zuwa gare shi.
2. Idan a cikin wannan karkara rike biyu a layi daya guitar, sa'an nan da baka yanke su, kuma a kewaye tsakanin su ne daidai.
3. Zana biyu guitar PR da kuma [QS], intersecting a cikin da'irar a aya T. The samfurin na daya tsirkiya tsawo za su kasance kullum daidai da samfurin na sauran tsirkiya tsawo, Ina nufin x PT TR = QT x TS.

Karkara: janar ra'ayi da kuma asali dabara

Daya daga cikin muhimman halaye na wannan lissafi siffar ne a karkara. Da dabara aka samu ta yin amfani da dabi'u irin su radius, diamita da kuma m "π", wanda ya nuna da haƙuri da rabo daga karkara zuwa da diamita.

Saboda haka, L = πD, ko L = 2πR, inda L - shi ne mai circumferential tsawon, D - diamita, R - radius.

Formula circumferential tsawon za a iya gani a matsayin tushen lokacin da radius ko diamita na wani ba karkara: D = L / π, R = L / 2π.

Mene ne da'irar: na asali postulates

1. Direct da karkara iya zubar a kan wani jirgin saman kamar haka:

• da wani maki a na kowa.
• da daya batu a na kowa, na layin da ake kira tangent: idan ka rike wani radius ta tsakiya da kuma batu na lamba, shi zai zama perpendicular zuwa tangent.
• da maki biyu a cikin kowa, da kuma layin da aka kira da yanke.

2. Bayan uku sabani da maki kwance a daya jirgin sama, ba zai iya rike fiye da daya karkara.

3. biyu da'irori iya zo a cikin lamba a daya kawai batu, wanda aka located a kan layi kashi a haɗa da cibiyoyin wadannan da'irori.

4. A cikin wani rotations game da cibiyar daga cikin da'irar a cikin kanta.

5. Mene ne da'irar daga ra'ayi na fasali?

• guda curvature daga cikin layi a kowane batu;
• tsakiyar fasali zumunta nuna Yã;
• madubi fasali game da diamita.

6. Idan ka gina wani biyu rubũtacce malã'iku, bisa wannan baka da wani da'irar, za su zama daidai. Angle subtended da wani baka daidai rabin na karkara, Ina nufin warware tsirkiya-diamita, shi ne ko da yaushe 90 °.

7. kwatanta da rufaffiyar mai lankwasa Lines daga cikin wannan tsawon, shi dai itace cewa karkara rabo delimits jirgin sama na mafi girma yankin.

A da'irar rubũtacce a alwatika da kuma bayyana game da shi

Wannan mas'ala cewa irin wannan da'irar ba zai zama cikakken ba tare da wani bayanin siffofin na da dangantaka da na lissafi da siffar da triangles.

1. A gina wani da'irar rubũtacce a alwatika, ta cibiyar za ta ko da yaushe zo daidai da batu na rarrabawa da bisectors na kusassari na alwatika.
2. A cibiyar da'irar da aka bayyana game da alwatika, located a rarrabawa da tsakãtsaki ce perpendiculars to kowane gefe na alwatika.
3. Idan ka bayyana a da'irar a kusa da dama alwatika, sa'an nan ta tsakiya za a located in tsakiyar hypotenuse, wato, da karshen za su zama a diamita.
4. A cibiyoyin na rubũtacce da circumscribed da'irori zai zama guda batu, idan tushe ne zuwa shirya wani equilateral alwatika.

Babban zargin daga cikin da'irar da kuma quadrangles

1. Around da convex quadrilateral ne mai yiwuwa a bayyana a da'irar kawai a lokacin da Naira Miliyan Xari da ta daura ciki kusassari karkacewa 180 °.
2. Sana'anta rubũtacce a convex quadrilateral da'irar ne yiwu idan wannan Naira Miliyan Xari da tsawo na tarnaƙi.
3. Bayyana a da'irar game da wani parallelogram iya zama idan ta kusassari.
4. Rubũtacce a parallelogram da'irar iya zama a idan duk sãsanninta ne daidai, wato, shi ne wani rhombus.
5. Yi wata da'ira ta cikin trapezoid sasanninta iya zama kawai idan shi ne isosceles. Duk da haka, tsakiyar circumscribed da'irar da aka located a rarrabawa da axis na fasali na quadrilateral da tsakãtsaki ce perpendicular kõma zuwa gefe.