| Euclid, John Keill - Geometry - 1733 - 444 pages
...Therefore the J 31 other Angles BAD, ABD, are * equal to one Right * y.. i. Angle. But the Angle ABF, is alfo a Right Angle : Therefore the Angle ABF, is equal to the Angles BAD, ABD; and if ABD, which is common, be taken away, then the Angle DBF remaining, will be... | |
| Robert Simson - Trigonometry - 1762 - 488 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... | |
| Euclid - Geometry - 1765 - 492 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... | |
| John Keill - Geometry - 1772 - 462 pages
...touching it that are in the fame Plane r But BF, being in the faid Plane, touches it ; where- • fore the Angle ABF is a Right Angle : But the Angle ABC...; and fo the Right Line BC, is not above the Plane pafling thro' BE and B D. Wherefore the threeRight Lines BC, BD, BE, are in one and the fame Plane.... | |
| Robert Simson - Trigonometry - 1775 - 534 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 - 552 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 - 534 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... | |
| Euclid, John Playfair - Euclid's Elements - 1795 - 462 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 - Trigonometry - 1799 - 374 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 - 530 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 impoflibfe. therefore the ftraight line BC is not above the plane in which are BD and BE. wherefore... | |
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