[301.] Problema IX. Tab. XIV. fig. 3. Triangulum E A I, diſtantia Leidæ & Waſſenariæ quæſita.

[302.] Problema X. Tab. XIV. fig. 6. Triangulum A E I, Leida, Waſſenaria, Voorſchooten.

[303.] Problema XI. Tab. XV. fig. 10. Triangulum aie, Leida, Noortvicum, Voorſcbooten.

[304.] XII. Problema. Tab. XV. fig. 9. Diſtantia inter Leidam & Noortvicum alio modo quæſita.

[305.] XIII. Problema Tab. XV. fig. 11. Triangulum A E B, Haga, Leida, Noortvicum.

[306.] XIV. Problema. Eadem diſtantia inter Hagam & Leidam aliter tentata.

[307.] XV. Problema. Triangulum A E S nectens Leidam, Hagam, Goudam.

[308.] Problema XVI. Triangulum E S R. Leida, Gouda, Dordracum.

[309.] Problema XVII. Triangulum E A R, Leida, Haga, Dordracum.

[310.] Problema XVIII. Triangulum A E F, Haga, Leida, Rotterodamum.

[311.] Problema. XIX. Triangulum E S F, Leida, Gouda, Rotterodamum.

[312.] Problema XX. Triangulum E S V. Leida, Vltrajectum, Gouda.

[313.] Problema XXI. Triangulum E R V, connectens Trajectum, Leidam, Dordracum.

[314.] Problema. XXII. Triangulum E M V. Leida, Oudewatera, Vltrajectum.

[315.] Problema XXIII. Triangulum E M S. Leidam, Oudewateram & Gou-dam connectens.

[316.] Problema XXIV. In Triangulo A E I Haga, Leida, Harlemum.

[317.] Problema XXV. Tab. XV. fig. 15. Diſtantia inter Harlemum & Leidam alio modo quæſita in Triangulo I A E.

[318.] Problema XXVI. Tab. XVI. Triangulum O E V, Amſtelodamum, Leida, Vltrajectum.

[319.] Problema XXVII. Triangulum E I V, Leida, Harlemum, Vltra-jectum.

[320.] Problema XXVIII. Triangulum E I O, Leida, Harlemum, Amſtelo-damum.

[321.] Problema XXIX. Triangulum I O ?, Harlemum, Amſtelodamum Alcmaria.

[322.] Problema XXX. Triangulum E O ? Leida, Amſtelodamum, Alcmaria.

[323.] Problema XXXI. Triangulum M V L, Oude-Watera, Vltrajectum, Bommelia.

[324.] Problema XXXII. Trangulum R V L, Dordracum, Trajectum, Bommelia.

[325.] Problema XXXIII. Triangulum E V L. Leida, Trajectum, Bommelia.

[326.] Problema XXXIV. Triangulum ? E L, Alcmaria, Leida, Bommelia.

[327.] Problema XXXV. Triangulum R L V. Dordracum, Bommelia, Breda.

[328.] Problema XXXVI. Triangulum R S F. Dordracum, Gouda, Rotterodamum.

[329.] Problema XXXVII. Triangulum R T F, Dordracum, Willemſtadium, Rotterodamum.

[330.] Problema XXXVIII. Triangulum R T V. Dordracum, Willemſtadium, Breda.