Me ngā hanganga e rua he porotaka pūwero, he whakarara rānei, me ngā pupuri i hangaia ki te rau maitai, ki te kapia hangai rānei, ko te āhuatanga o ngā peera ko ō rātou ara porowhita o waho e āhei ai te hē o te whakarara i roto i te 3° te piko i waenga i te mowhiti o roto me te mowhiti o waho, kia ea ai ngā hapa kōpikopiko me te piko.
