 | John Mitchell Mason - Presbyterian Church - 1849 - 604 pages
...certainty. In mathematical reasoning, our knowledge is greater than our ignorance. When you have proved that the three angles of every triangle are equal to two right angles, there is an end of doubt; because there are no materials for ignorance to work up into phantoms ; but... | |
 | Thomas Brown, James Parkinson Boyle - Philosophy - 1849 - 370 pages
...If then we can only enunciate, but not conceive, a general proposition, we can never be certain that the three angles of every triangle are equal to two right angles, until it has been demonstrated of triangles of every variety of figure ; and before this can be done,... | |
 | John F. Heather - Scientific apparatus and instruments - 1849 - 208 pages
...two angles H i A and '-A HA i ; and because the vertical angles A v H and iv E are equal, and that the three angles of every triangle are equal to two right angles, therefore the two angles VIE and s EH are, together, equal to the two angles AH v and HA i, and therefore... | |
 | Edward Beecher - Baptism - 1849 - 368 pages
...not a head for the philosophy of language : and I say this with as little bad feeling as I say that the three angles of every triangle are equal to two right angles." This is certainly an illustrious specimen of genuine Attic Salt. Dr. Carson, no doubt, has monopolized... | |
 | Samuel Bailey - Logic - 1851 - 254 pages
...fallible, or that the three angles of the triangle before me are together equal to two right angles, because the three angles of every triangle are equal to two right angles. The dictum, then, is obviously one of those selfevident maxims which we have above described, and it may... | |
 | William Walton - Coordinates - 1851 - 446 pages
...four points, and of which the major axes are parallel or perpendicular to one another : to prove that any two of its opposite angles are together equal to two right angles. 7. Two concentric ellipses, which have their axes in the same directions, intersect, and four common... | |
 | Popular educator - 1852 - 842 pages
...reason of this construction is plain, .. ~~r from Prop. XXXII., Book I., Euclid, which asserts that the three angles of every triangle are equal to two right angles; and from Prop. XIII., Book I., which asserts that the anglet which one straight line mates with anoiJier... | |
 | Royal Military Academy, Woolwich - Mathematics - 1853 - 400 pages
...PROPOSITION XXII. THEOR. The opposite angles of any quadrilateral figure inscriled in a circle, are together equal to two right angles. Let ABCD be a quadrilateral...because the three angles of every triangle are equal (32. I.) to two riffht angles, the three angles of the triangle CAB, viz., the angles CAB, ABC, BCA... | |
 | Euclides - 1853 - 146 pages
...XXII. THEOREM. The opposite angles of any quadrilateral figure inscribed in a circle, are together equal to two right angles. Let ABCD be a quadrilateral...opposite angles are together equal to two right angles. 1) Join AC, BD; and because the three angles of every triangle are equal (I. 32.) to two right angles,... | |
 | Euclides - Geometry - 1853 - 176 pages
...are together equal to two right angles. LET ab С d be a quadrilateral figure in the circle ab С d ; any two of its opposite angles are together equal to two right angles. Join a С, bd ; and because the three angles of every triangle are equal (i. 32) to two right angles, the... | |
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The opposite angles of any quadrilateral figure described in a circle, are toe/ether equal to two right angles. Let ABCD be a quadrilateral figure in the circle ABCD : any two of its opposite angles are together equal to two right angles. 
