Nzira yekuwana sei mhirizhonga ye polygon?

Kunyange kubva kuchikoro chepuraimari, vazhinji vanoyeuka maitiro ekuwana rutivi rwemhizha chero ipi zvayo yeiometri: zvakaringana kuziva urefu hwemativi ose uye kuwana huwandu hwavo. Chiyero chenguva yakakwana yemiganhu yenhamba ye ndege. Mune mamwe mazwi, ichi ndicho chiyero chemarefu emativi ayo. Chiyero chekuyera kwechimiro chinofanira kufanana nechiyero chekuyera kwemativi acho. Chimiro chemuviri weipoloni ine fomu P = a + b + c ... + n, apo P ndiyo inoperera, uye pano, b, c uye n ndiwo urefu hwemativi ose. Kana zvisina kudaro, kureba kwendenderedzwa (kana kutenderera kwendenderedzwa) inotariswa: chirevo p = 2 * π * r chinoshandiswa, iyo r radius uye π inhamba inogara inosvika 3.14. Ngatitarisei mimwe mienzaniso iri nyore inoratidza zvakajeka kuti ungawana sei mhirizhonga. Semuenzaniso, tinotora zviyero zvakadai sekwereti, rectangle, katatu, parallelogram, uye denderedzwa.

Nzira yekuwana nayo chiyero chekwereti

Nzvimbo yakareruka inogara yakagadzirwa ne quadrilateral, iyo mativi ose nemakona akaenzana. Sezvo mativi ose emakona akaenzana, chiyero chehurefu hwemativi acho chinogona kuverengwa nechirevo P = 4 * a, uko pane urefu hweimwe yemativi. Nokudaro, chiyero chekwereti ine rutivi rwema 16,5 cm ndiP = 4 * 16.5 = 66 cm.Unogonawo kuverenga mutezo we equilateral rhombus.

Nzira yekuwana nayo chiyero chekatekete

Rutsanga ndeye quadrilateral ine mazenga ose akaenzana ne 90 degrees. Zvinonyatsozivikanwa kuti mumufananidzo wakadai seakatekete, urefu hwemativi acho hwakaenzana muhuviri. Kana kupamha nekukwirira kwekwangwani kune urefu hwakafanana, zvino inonzi yakakona. Kazhinji kureba kwekatekete kunonzi kureba kwemativi, uye upamhi ndicho chiduku. Nokudaro, kuti uwane rutivi rwekandeti, iwe unofanirwa kuwedzera kaviri chiyero chehupamhi hwacho nekukwirira: P = 2 * (a + b), uko pakakwirira uye b kubhiti. Kuva nerutsanga, rumwe rutivi rwakareba masendimita gumi nemashanu uye rumwe rutivi nehupamhi hunotarisirwa ne5 cm, tinowana mamiriyoni akaenzana neP = 2 * (15 + 5) = 40 cm.

Nzira yekuwana nayo mhirizhonga yekatatu

Iyo katatu inoumbwa nezvikamu zvitatu zvinosangana pamakona (maziso emutatu) asingatauri pamutsara wakarurama. Nhatu-katatu inonzi inofananidzwa, kana dzose dzayo nhatu dzikaenzana, uye isosceles kana kune mairi maviri akaenzana. Kuti uwane rutivi rwekuenzanisa katatu, zvakakosha kuwedzera urefu hwerutivi rwaro ne 3: P = 3 * a, pane imwe yemativi ayo. Kana mativi emakatatu asina kuenzana, zvakakosha kuita basa rekuwedzera: P = a + b + c. Chimiro che isosceles katatu nekweshure 33, 33 uye 44, zvichienderana, chichava: P = 33 + 33 + 44 = 110 cm.

Nzira yekuwana nayo mhirizhonga yeparallelogram

Parallelogram inonzi quadrilateral pamwe chete nechepamukati yakatarisana nemativi. A square, rhombus uye rutsanga ndiwo maitiro chaiwo emufananidzo. Mativi akasiyana-siyana eparallelogram imwe yakaenzana, saka kuverenga purogiramu yacho yatinoshandisa pombi P = 2 (a + b). Mu parallelogram nemativi akareba masendimita makumi matanhatu nemasere uye masendimita gumi nemashanu, chiyero chemativi acho, kana kuti kupera, P = 2 * (16 + 17) = 66 cm.

Nzira yekuwana nayo denderedzwa yendenderedzwa

Denderedzwa iri mutsara wakavharwa, zvese zvinowanikwa pane imwe nzvimbo yakaenzana kubva pakati. Nharaunda yacho uye kubwinya kwayo nguva dzose ine chiyero chakafanana. Ichi chiyero chinoratidzirwa nehuwandu, yakanyorwa uchishandisa tsamba π uye inenge 3.14159. Chimiro chendenderedzwa chinogona kuwanikwa kubva pachigadzirwa chemairasi ne2 uye ne π. Icho chinotarisa kuti urefu hwetenderedzwa ne-radius ye 15 cm huchaenzana ne P = 2 * 3.14159 * 15 = 94.2477