 | Thomas Stantial - 1859 - 352 páginas
...and all the angles made by any number of lines meeting in a point are equal to four right angles. B. The three angles of every triangle are equal to two right angles. C. The angles at the base of an isosceles triangle are equal to one another. D. Construct a parallelogram... | |
 | Popular educator - 1860 - 424 páginas
...required. The reason of this construction is plain, „ from Prop. XXXII., Book I., Euclid, which asserts that the three angles of every triangle are equal to two right anglet; and from Prop. XIII., Book I., which asserts that the anglei "/in-/, one straight line ma/tes... | |
 | Robert Potts - 1860 - 380 páginas
...any two of its opposite angles shall together be equal to two right angles. Join 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... | |
 | William Thomas Read - 1862 - 144 páginas
...already proved may be obtained, which shows them to be true for any triangle. • We know (by Eu. 1, 32), that the three angles of every triangle are equal to two right angles ; therefore those of ABC are equal to two right angles ; and since B = 90°, therefore A + C = 90°,... | |
 | Euclides - 1862 - 172 páginas
...together equal to two right angles. CONSTRUCTION Draw the diagonals AC and DB. 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... | |
 | Euclides - 1864 - 448 páginas
...two of its opposite angles shall together be equal to two right angles. c Join 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... | |
 | Robert Potts - 1865 - 528 páginas
...any two of its opposite angles shall together bfe equal to two right angles. Join 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... | |
 | Euclides - 1865 - 402 páginas
...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 - 1866 - 228 páginas
...to 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... | |
 | Robert Potts - 1868 - 434 páginas
...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... | |
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When you have proved that the three angles of every triangle are equal to two right angles... 
