Valerio, Luca, De centro gravitatis solidorvm libri tres
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              huius ſeſquialtera BEF: & ſumpta axis BD quarta par­
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              te DF, & tertia DG: qua ratione erit FG duodecima
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              pars axis BD quarta ab ea, cuius terminus D; fiat vt
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              IB ad BD, ita FH ad HG. </s>
              <s>Dico conoidis, vel portio­
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              nis ABC centrum grauitatis eſſe H. </s>
              <s>Nam vt eſt EB
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              ad BD ita fiat DK ad KA: & ponatur KDY ſeſqui­
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              altera ipſius DK, & ex AK abſcindatur KM ſubſeſ­
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              quialtera ipſius AK: & ipſis DK DM, DA, æquales
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              eodem ordine abſcindantur DL, DN, DC: & deſcri­
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              bantur triangula, KBL, MBN: & per puncta ABC
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              vertice communi B, tranſeant duæ ſectiones parabolæ
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              AOB, & BPC, ita vt contingat recta BK parabolam
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              AOB, recta autem BL parabolam BPC; ſit autem
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              AKLC, parabolarum diametris parallela,. Deinde
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              ſecto axe BD bifariam, & ſingulis eius partibus rurſus bi­
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              fariam in quotlibet partes æquales, ſint ex illis duæ
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              partes DQ, QF: & per puncta QF planis quibuſdam
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              baſi parallelis ſecentur vnà ſolidum & hyperbole ABC:
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              ſintque hyperboles ſectiones, quæ continent ſectiones trian
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              gulorum ABC mixti, & rectilinei KBL, rectæ RTX
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              ZVS:
                <foreign lang="grc">αγεζδβ. </foreign>
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              <s>ſolidi autem ABC ſectiones erunt cir­
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              culi, vel ellipſes ſimiles baſi circa diametros RS,
                <foreign lang="grc">αβ</foreign>
              .
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              <s>Quoniam igitur eſt vt
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              K ad KD, ita AK ad KM;
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              vtrobique enim eſt proportio ſeſquialtera: erit permutan­
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              do vt YK ad A
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              K
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              , hoc eſt vt IB ad BD, vel FH, ad
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              HG, ita D
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              K
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              ad
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              K
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              M, hoc eſt triangulum BDK ad
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              triangulum BKM, hoc eſt ad æquale huic ex demon­
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              ſtratis triangulum A
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              K
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              B mixtum: hoc eſt in duplis ita,
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              triangulum BKL ad duo mixta rriangula AKB, BLC
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              ſimul. </s>
              <s>ſed duorum triangulorum AKB, BLC ſimul eſt
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              centrum grauitatis F, vt in hoc tertio libro demonſtra­
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              uimus: trianguli autem BKL, vt in primo, centrum gra­
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              uitatis G; totius igitur trianguli ABC centrum graui­
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              tatis erit H. </s>
              <s>Rurſus quoniam eſt vt BD ad BQ hoc </s>
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