Manasara 18.80

18.80

mānaṃ prāguktavatkuryātpuṃstrī ceṣṭakāṃ viduḥ
mūlāgraṃ ca samatāraṃ tu ceṣṭakā puruṣa smṛtam

One should make the measurement as stated before; the wise know the male and female brick.
The brick whose base and top have equal width is known as the male brick;