| Isaac Sharpless - Geometry - 1879 - 282 pages
...circle are together equal to two right angles. Let AB CD be a quadrilateral figure in the circle AB CD; **any two of its opposite angles are together equal to two right angles. Join AC, BD.** The angle CAB is equal (III. 17) to the angle CDB, because they are in the same segment BADC, and the... | |
| Royal Philosophical Society of Glasgow - Science - 1879 - 636 pages
...of acting independently of each other, and in co-operation with each other. When I demonstrate that **the three angles of every triangle are equal to two right angles,** or that in a righi^angled triangle the square upon the side subtending the right angle is equal to... | |
| Isaac Todhunter - Euclid's Elements - 1880 - 426 pages
...than a semicircle, is less than a right angle. And because ABCD is a quadrilateral figure in a circle, **any two of its opposite angles are together equal to two right angles** ; [III. 22. therefore the angles ABC, ADC are together equal to two right angles. But the angle ABC... | |
| Euclides - Euclid's Elements - 1881 - 236 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...angles are together equal to two right angles. Join AC** and B D. The angle CAB is equal to the angle CDB (III. 21), because they are in the same segment CDAB.... | |
| Education, Higher - 1883 - 536 pages
...a quadrilateral have two of its opposite sides parallel, and the two others equal but not parallel, **any two of its opposite angles are together equal to two right angles.** 15. If a solid angle be contained by three plane angles, any two of them are together greater than... | |
| John Carroll (art master.) - Geometry - 1881 - 100 pages
...angle at M. Produce the lines till they meet in O. The angle at O will be equal to the angle at N ; for **the three angles of every triangle are equal to two right angles.** — Euclid i. 32 cor. Problem 15. — To construct an isosceles triangle, the base FG and the vertical... | |
| Thomas Low Nichols - 1881 - 134 pages
...abstinence, which is safe and sure. All this is like saying over and over again, two and two make four : **the three angles of every triangle are equal to two right angles** : things which are equal to the same thing are equal to each other. A natural diet is always a condition... | |
| Isaac Sharpless - Geometry - 1882 - 292 pages
...18. Theorem. — The opposite angles of any quadrilateral figurt described in a circle are together **equal to two right angles. Let ABCD be a quadrilateral...are together equal to two right angles. Join AC, BD.** The angle CAB is equal (III. 17) to the angle CDB, because they are in the same segment BADC, and the... | |
| Euclid, Isaac Todhunter - Euclid's Elements - 1883 - 426 pages
...than a semicircle, is less than a right angle. And because ABCD is a quadrilateral figure in a circle, **any two of its opposite angles are together equal to two right angles** ; [III. 22. therefore the angles ABC, ADC are together equal to two right angles. But the angle ABC... | |
| John Fry Heather - Scientific apparatus and instruments - 1884 - 566 pages
...the two interior angles HIA and HAT; and because the vertical angles ATH 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 angle? AK v and HA i, and therefore... | |
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