Chidzudzani (Congruency) zvinoreva kuti zvivakwa zviviri zvine chiumbwa (shape) chakafanana uye hukuru (size) hwakaenzana. Izvi zvoreva kuti chiumbwa chokutanga chinokwanisa kushandurwa mamiriro kusvikira chati gedye-gedye kupindirana nechiumbwa chepiri; zvimwechitezvo tichitanga kushanda nechiumbwa chepiri.