| Popular educator - 1860
...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 - 361 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
...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
...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... | |
| Robert Potts - 1864
...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... | |
| Alexander Kennedy Isbister - 1865
...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 - 185 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 - 410 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... | |
| John Fry Heather - 1871
...to the two interior angles ni A and HAI; 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 TIE and s EH are, together, equal to the two angles AH v and HAI, and therefore... | |
| John Reynell Morell - 1871 - 131 páginas
...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 follows... | |
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