1 4 ſe mutuo tangentium, nec indirectum

Ücentium, alterius ad alteram incli-

natio. Fſtquevel reclus, Vel obliquust--

V. Angelus rectus eſt cujus crura- ad ſe invicem ſunx perpendicularia. VI. Angulus obliquus eſt, cujus

eruraad ſeinvicem ſumtanclinata, Eſf

pe/ obeuſuu vel acutus. VIl. Obrtuſus eſt, qui major rect, cxiſtit.

VIII. Acutus eſt, qui minor recté

exiſtier II. Teorematzs. I. Linea perpendicvlariter intidens in

Üüneam rettam ſubratam facis Auot au-

gulo⸗ eονν

II. Livea perpenditularhtor ſecans ie

geam /ta faci, gaaruor angulö, relor,

Ifl. Linca obliquè ingidens in aliam re-

Ham facis duos argalos obliquos, unum obtuſfum, alterum reclam.

IV. Quilibe: 4nulus 7eHlus dicit ur 68 vouaginta graduum; quia angulus re- Aus menſuratur ab arcu Lireyli, laäu

Ilyir