He rerekē ngā rahi o te hanganga, ā, ko ngā mea paerewa ko: 21*41/41*41, 41*62, 41*82, me ētahi atu. Ka taea e te mīhini kotahi te hanga i ngā rahi rerekē, ka taea te whakamahi i te hoahoa whakarerekētanga aunoa katoa, te hoahoa rīpene rānei, te whakarerekē rānei i ngā roera mā te whakamahi i ngā hiri.
He whānuitia te whakamahinga o ngā kōtaha hanganga, ehara i te mea he whānuitia te whakamahinga mō te tautoko i te rā anake, engari mō te tautoko ārai-rū whenua hoki, nā tōna kaha teitei me te ngāwari o te tāutanga, kua whānuitia te tūtohutanga me te whakamahinga e te umanga hanga.