[21.] SCHOLIVM.
[22.] THEOREMA 3. PROPOSITIO 4.
[23.] COROLLARIVM.
[24.] THEQREMA 4. PROPOSITIQ 5.
[25.] COROLLARIVM.
[26.] THEOREMA 5. PROPOSITIO 6.
[27.] SCHOLIVM.
[28.] COROLLARIVM.
[29.] THEOREMA 6. PROPOSITIO 7.
[30.] COROLLARIVM.
[31.] PROBLEMA 2. PROPOSITIO 8.
[32.] SCHOLIVM.
[33.] LEMMA.
[34.] LEMMA PRIMVM.
[35.] LEMMA II.
[36.] LEMMA PRIMVM.
[37.] LEMMA II.
[38.] THEOREMA 7. PROPOSITIO 9.
[39.] SCHOLIVM.
[40.] THEOREMA 8. PROPOSITIQ 10.
[41.] COROLLARIVM.
[42.] SCHOLIVM.
[43.] THEOREMA 9. PROPOSITIO 11.
[44.] SCHOLIVM.
[45.] COROLLARIVM PRIMVM.
[46.] COROLLARIVM II.
[47.] THEOREMA 10. PROPOSITIO 12.
[48.] COROLLARIVM.
[49.] THEOREMA 11. PROPOSITIO 13.
[50.] THEOREMA 12. PROPOSITIO 14.