 | Euclides - 1865 - 402 pages
...together equal to two right angles. CONSTRUCTION Draw the diagonals AC and I)B. DEMONSTRATION Because the three angles of every triangle are equal to two right angles, (I. 32) the three angles of the triangle CAB, viz. the angles CAB, ABC, BCA, are equal to two right... | |
 | John Fry Heather - Mathematical instruments - 1866 - 228 pages
...the two angles HI A and '•* HA i ; and because the vertical angles AVH and IVE 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... | |
 | Gerardus Beekman Docharty - Geometry - 1867 - 474 pages
...A, O ; B, O j C, O ; D, O ; E, O ; Then, since the sum of all the angles of every triangle is always equal to two right angles, the sum of all the angles of the triangles ABP, BBC, .... about the point P, will be equal to the sum of all the angles of the equal... | |
 | Robert Potts - 1868 - 434 pages
...two of its opposite angles shall together be equal to two right anglss. .0 Jam AC, BD. And because the three angles of every triangle are equal to two right angles, (I. 32.) the three angles of the triangle CAB, viz. the angles CAB, ABC, BCA, are equal to two right... | |
 | John Fry Heather - Drawing instruments - 1871 - 224 pages
...two interior angles H i A and HA i ; and because the vertical angles AVH 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 SEE are, together, equal to the two angles AH v and HA i, and therefore... | |
 | John Reynell Morell - Geometry - 1871 - 156 pages
...quadrilateral is divided into two triangles, whose angles form those of the quadrilateral ; and as the three angles of every triangle are equal to two right angles or 180°, the angles of the quadrilateral must be equal to four right angles or 300°. From this it... | |
 | Arthur Young - Meditation - 1873 - 222 pages
...it is compelled to affirm, and does affirm this, with the same confidence as the propositition that the three angles of every triangle are equal to two right angles, or that two bodies cannot occupy the same space. Even this, notwithstanding it lies at the foundation... | |
 | Euclides - 1874 - 342 pages
...shall together be equal to two right angles. Construction. Join AC, BD. Demonstration. And because the three angles of every triangle are equal to two right angles (I. 32), the three angles of the triangle CAB, viz., 1. The angles CAB, ABC, BCA are equal to two right... | |
 | Robert Potts - Geometry - 1876 - 446 pages
...any two of its opposite angles shall together be equal to two right angles. Join ^ C, BD. And because the three angles of every triangle are equal to two right angles, (I. 32.) the three angles of the triangle CAB, viz. the angles CAB, ABCt BCA, are equal to two right... | |
 | Elias Loomis - Conic sections - 1877 - 458 pages
...sixth part of four right angles (Pr. 2, Sch. 1), or the third part of two right angles. Also, because the three angles of every triangle are equal to two right angles, the two angles OAB, OBA are together equal to two thirds of two right angles ; and since AO is equal to... | |
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When you have proved that the three angles of every triangle are equal to two right angles... 
