baɪ wˈɛl nˈoʊn ɹɪzˈʌlts ˌɔn ɐ kjˈuːbɪk sˈɜːfɪs, ðə nˈʌmbɚɹ ʌv lˈaɪnz ðæt kˈʌts tˈuː dɪsdʒˈɔɪnts lˈaɪnz ɪz fˈaɪv, ðˈʌs wiː ɡɛt sˌiːˈɛs tˈuː ˈiːkwəlz sˌiːˈɛs sˌiːtˈiː ˈiːkwəlz fˈaɪv.
By well known results on a cubic surface, the number of lines that cuts two disjoints lines is 5, thus we get (Cs) 2 =Cs Ct=5.