 | John Playfair - Mathematics - 1806 - 320 pages
...in that plane ; therefore the angle ABF is a right angle. But, by the Viypothesis, the angle ABC is a right angle ; therefore the angle ABF is equal to the angle ABC ; and they are both in -the same Suppl. plane, which is impossible. Therefore the straight line BC wv^/ is not above the plane... | |
 | Robert Simson - Trigonometry - 1806 - 546 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... | |
 | Euclides - 1816 - 588 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 impossible ; Therefore the is straight line BC is not above the plane in which ape... | |
 | John Playfair - 1819 - 354 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... | |
 | Peter Nicholson - Mathematics - 1825 - 1046 pages
...consequently the other two angles BAD, ABD are equal (32. I.) to a right angle : But ABF it likewise a right angle ; therefore the angle ABF is equal to the angle* BAD, ABD : Take from these equals the common angle ABD ; therefore the remaining angle DBF is equ;il... | |
 | Robert Simson - Trigonometry - 1827 - 546 pages
...plane, 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 isf ^^-- E t 9 Ax. impossible; therefore the straight line BC is not above the plane... | |
 | Euclid - 1835 - 540 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... | |
 | A. Bell - Conic sections - 1837 - 180 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... | |
 | Euclides - Geometry - 1841 - 378 pages
...plane 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 * 9 Ax. ABC, and they are both in the same plane, which is* impossible: therefore the straight line... | |
 | Euclides - 1842 - 316 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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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 BD and BE: wherefore, the three straight lines BC, BD, BE are in one and the same plane. Therefore, if three straight lines,... 
