Ummandla ngummandla onqamleza amacala kwipoligoni. Isetyenziswa ngokubanzi kubomi babantu bemihla ngemihla, umzekelo, xa kulinganiswa umhlaba okanye indawo. Ixabiso lendawo liyahluka ngokobume bayo. Ipoligoni nganye inesimo sayo, ngoko nganye inendlela eyahlukileyo yokubala indawo yayo. Ezinye zeepoligoni ezininzi ezaziwayo zezi uxande kunye seZizwe.

Zombini ezi ndawo zibalwa ngokuphinda-phinda umlinganiso wobude ngemilinganiselo ebanzi nganye. Yonke imilinganiselo kufuneka ikwicandelo elinye lobude ukufumana ixabiso elichanekileyo.

Rectangle

Zimbini iintlobo ezahlukeneyo zoxande, eyokuqala yile inamacala onke afanayo, abizwa ngokuba sisikwere, kwaye anamacala ahlukeneyo.

Ukubalwa koxande kunokwenziwa ngolu hlobo lulandelayo

A = b. h

Oko kukuthi, ukuba nendawo yoxande kufuneka siphindaphinde ixabiso lesiseko soxande nokuphakama kwalo. Ngolu phindaphindo uya kuba neziphumo zommandla woxande.

Umzekelo: xa isiseko soxande siyi-6 kwaye ukuphakama kuyi-4, indawo leyo kufuneka ibalwe ngokuphindaphinda la maxabiso mabini.

A = 6.4

H = 24 cm²

Indawo iyakuba yi-24 cm²

isikwere

Isizathu sokufumana indawo yesikwere iyafana naleyo yoxande, kufuneka uphindaphinde umlinganiso wesiseko ngomlinganiso wobude, kodwa owahlukileyo koxande, isikwere sinamacala afanayo, ke kukho umahluko omncinci kwifomula yayo.

Kuba la macala mabini ayalingana, omabini achazwe ngu "l", ke ngoko ifomula iya kujongeka ngoluhlobo:

A = 1. l

O

A = l²

Iipolgoni ezinemimandla efana nexande kunye nekwere.

Ezinye iipoligoni ezinemilo yokubala imilo efana nesikwere kunye noxande zinokuqaqanjiswa. Njenge:

El Paralelogramo enefomula yokubala indawo elingana noxande. Inamacala amane, apho ukuphakama kwayo kuphindaphindwa sisiseko ukunika iziphumo zommandla wayo. Ukuba yindawo yayo: A = bh

El TriánguloNgaphandle kokungabi namacala amane, zintathu kuphela, unxantathu ulinganisa isiqingatha soxande, apho oonxantathu ababini bangena kuxande, ngoko ke ummandla kanxantathu sisiseko esiphindaphindwe ngobude obohlulwe kabini. Ke ngoko: A = bh / 2