A history of this form.
96 4X24 1 1 0 0 B 60+60=120 12+12=24 6 144 24 24 C 60+60=120 14+10,/.=241/j 5 »/, 140 20 20 B 60+ 60=120 12+15 =27 6 162 42 42 C 60+60=120 14+10,/.=241/j 5 »/, 140 20 20 D 60+60=120 16+16=32 7Vj 240 120 4x30 E 60+ 60=120 10‘/a+14=24‘/t «*/t 168 48 2x24.