Manasara 57.23

57.23

tasyādhaścaikaviṃśāntamūrudīrghaṃ guṇāṃśakam
jānujaṅghorutulyaṃ syātpādajānusamocchrayam

below that, down to twenty-one [parts] is the length of the thigh; the knee is three parts; / the shank should be equal to the thigh, and the height of the foot equal to the knee;