| John Keill - Logarithms - 1723 - 364 pages
...Right Angle. Therefore the+jj.^^ other Angles BAD, ABD, are equal to one Right Angle. But the Angle ABF **is alfo a Right Angle: Therefore the Angle ABF, is * equal to the** Angles* jz. i. BAD, ABD; and if ABD, which is common, be taken away, then the Angle DBF remaining,... | |
| Robert Simson, Euclid - Trigonometry - 1762 - 466 pages
...that plane meets it. therefore the angle ABF is a right angle ; but the angle ABC, by the Hypothefis, **is alfo a right angle ; therefore the angle ABF is...equal to the angle ABC, and they are both in the fame** plane,which is impoffible. therefore the ftraight line BC is not above the plane in' which are BD and... | |
| Euclides, David Gregory - Mathematics, Greek - 1765 - 464 pages
...plans beneath, touches it : Therefore ABF is a right angle. But the angle ABC is alfo fupp.>fed to be **a right angle: Therefore the angle ABF is equal to...angle ABC; and they are both .in the fame plane; which** [by q. ax.] is impoffible. Therefore the right line EC is not above the plane beneath: Therefore the... | |
| Robert Simson, Euclid - Trigonometry - 1775 - 520 pages
...that plane meets it: Therefore the angle ABF is a right angle ; but the angle ABC, by the hypothefis, **is alfo a right angle ; therefore the angle ABF is...angle ABC, and they are both in the fame plane, which** is impomble : Therefore the ftraight line BC is not above the' plane in which are BD and BE: Wherefore... | |
| Euclid - 1781 - 520 pages
...that plane meets it: Therefore the angle ABF is a right angle ; but the angle ABC, by the hypothefis, **is alfo a right angle ; therefore the angle ABF is...angle ABC, and they are both in the fame plane, which** is impoflible : Therefore the ftraight line BC rs not above the plane in which are BD and BE : "Wherefore... | |
| Robert Simson - Trigonometry - 1781 - 466 pages
...that plane meets it. therefore the angle ABF is a right angle ; but the angle ABC, by the Hypothefis, **is alfo a right angle ; therefore the angle ABF is equal to the angle** A11C, and they are both in the fame plane, which is impoftible. therefore the ftraight line BC is not... | |
| John Playfair - Euclid's Elements - 1795 - 400 pages
...that plane meets it : therefore the angle ABF is a right angle ; but the angle ABC, by the hypothefis, **is alfo a right angle ; therefore the angle ABF is...angle ABC, and they are both in the fame plane, which** is impofuble : — therefore the ftraight line BC is not above the plane in which are BD and BE : Wherefore... | |
| Alexander Ingram, Robert Simson - Trigonometry - 1799 - 351 pages
...plane, meets it ; therefore the angle ABF is a right angle : but the angle ABC, by the hypothefis, **is alfo a right angle ; therefore the angle ABF is...angle ABC, and they are both in the fame plane ; which** is impoffible : Therefore the ftraight line BC is not above the plane in which are a 3. n. b 4. it.... | |
| Robert Simson - Trigonometry - 1804
...that plane meets it. therefore the angle ABF is a right angle ; but the angle ABC, by the Hypothefis, **is alfo a right ,angle; therefore the angle ABF is...angle ABC, and they are both in the fame plane, which** is impoflibfe. therefore the ftraight line BC is not above the plane in which are BD and BE. wherefore... | |
| Euclid, Robert Simson - Euclid's Elements - 1806 - 518 pages
...meets it : therefore the angle ABF is a right angle ; but the angle ABC, by the hypothesis, is also **a right angle ; therefore the angle ABF is equal to the angle ABC, and they are both in the** same plane, which is impossible: therefore the straight line BC is not above the plane in which are... | |
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