WhakamĀrama Āpitihanga
Ko ētahi wāhanga matua o te porowhita:
Mēnā ka tohua ētahi pūwāhi e rua i te paenga o te porowhita, ko te wāhanga iti o te paenga kei waenganui i aua pūwāhi, ka kīia he pewa iti. Ko te wāhanga nui o te paenga kei waenganui i aua pūwāhi, ka kīia he pewa matua:
Ina tuhia he rārangi torotika mai i tētahi pūwāhi i te paenga ki tētahi atu pūwāhi, ka kīia he aho o te porowhita. Ka hua ake he tapahanga iti, he tapahanga matua hoki:
Ina honoa ētahi pūwāhi e rua o te paenga me te pū o te porowhita, ka hua ake he pewanga iti, he pewanga matua hoki:
He pewa iti te wāhanga o te paenga kei waenganui i te M me te N. Ina honoa te M me te N ki tētahi atu pūwāhi i te paenga, ka hua ake he koki rāroto. He koki pū ka hua ake i te hononga o te M me te N ki te pū o te porowhita. He haurua te koki rāroto o te koki pū:
Mēnā he ōrite te rahi o ngā pewa e rua o te porowhita, he porowhita haurua ka hua ake. E 90° te rahi o te koki rāroto o tētahi porowhita haurua:
