Ta yaya aka ƙayyade kusurwar R na bututun murabba'i a cikin ma'aunin ƙasa?

Kusurwar R a cikin bututun murabba'i ita ce baka mai canzawa a mahaɗar jiragen sama biyu, wanda gabaɗaya shine rabin diamita na layin tsakiya na kusurwar baka mai lanƙwasa ta R. Darajar baka mai lanƙwasa ta R gabaɗaya shine sau 1.5 ~ 2.0 diamita na bututu. Girman kusurwar R ana ƙayyade shi ne bisa ga kauri na bango na bututun murabba'i. An raba kusurwar R zuwa kusurwar R ta ciki da kusurwar R ta waje. R ta ciki gabaɗaya tana da kauri sau 1.5 ~ 2. Ana iya samar da bututun ƙarfe mai murabba'i tare da kusurwoyin R daban-daban bisa ga buƙatun mai amfani.
Misali, ga bututun ƙarfe mai kusurwa huɗu mai baka mai zagaye R, A=1.0MM, diagonal=1.15MM, ta yaya za ku san kusurwar R? Idan bututun ƙarfe ne mai murabba'i mai baka, shin hanyar lissafi iri ɗaya ce? Mukulli mai kusurwa huɗu yana da tsawon A da faɗin B, diagonal na C, kuma radius na baka mai kusurwa huɗu R daidai yake. Lissafa girman R ta hanyar dabarar da ke ƙasa: (C/2-R) ^ 2=(A/2-R) ^ 2+(B/2-R) ^ 2 C ^ 2/4-CR+R ^ 2=A ^ 2/4-AR+R ^ 2+B ^ 2/4-BR+R ^ 2 4R ^ 2-4 (A+BC) R+(A ^ 2+B ^ 2-C ^ 2)=0.
Ya kamata a jaddada a nan cewa kusurwar R na bututun murabba'i mai kusurwa huɗu ba ya nufin baka, amma kusurwar tsakiya. Bakan yana nufin wani ɓangare a kan kewaye, kuma kusurwar layin da ke tsakanin ƙarshen baka biyu da tsakiya ita ce kusurwar tsakiya. Tunda kewayen da'ira shine 2 π R kuma kusurwar tsakiya da ta dace da ita ita ce 2 π, tsawon baka wanda ya dace da kusurwar tsakiya na naúrar shine 2 π R/2 π=R. Saboda haka, ana samun tsawon baka wanda ya dace da kowane kusurwar tsakiya a (radian unit)=aR. Hanyoyin aunawa da kayan aikin bututun murabba'i R kusurwa sun haɗa da ma'aunin R da mai nuna hoto. Ana iya amfani da ma'aunin R don maki masu kauri, mai nuna hoto don maki masu kyau, da kuma CMM don manyan buƙatu.