 | Charles William Weick - Geometrical drawing - 1925 - 276 pages
...between 90° and 180°. TRIANGLES 320. A triangle is any plane figure bounded by three straight lines. The sum of the three angles of any triangle is equal to 180°. If one of the angles is 90°, or a right angle, the sum of the other two is 90°. In radian... | |
 | John Charles Stone - Mathematics - 1926 - 344 pages
...by all three angles of the triangle? By trying this experiment with any triangle, you will find that The sum of the three angles of any triangle is equal to 180 degrees. 12. How many degrees in each angle of an equilateral triangle ? (The angles are all equal.)... | |
 | Education - 1893 - 650 pages
...Write two postulates and two axioms. 3. Define chord, segment, sector, polygon. 4. Demonstrate that the sum of the three angles of any triangle is equal to two right angles. 5. Demonstrate that any angle formed by a tangent and a chord is measured by one-half the intercepted... | |
 | Kenneth Sylvan Guthrie, David R. Fideler - Philosophy - 1987 - 374 pages
...parallel lines, which they used for the purpose of establishing by a general proof the proposition that the sum of the three angles of any triangle is equal to two right angles. This latter proposition they again used to establish the well-known theorems about the sums of the... | |
 | Ranan Banerji Ph.D. - Science - 2006 - 145 pages
...this and some other initial axioms he could deduce many facts about geometrical figures (for example, "the sum of the three angles of any triangle is equal to the sum of two right angles"). Now one of his axioms (about parallel lines) did not seem very obvious... | |
 | Engineering - 1883 - 562 pages
...opposite ; and the sum of the lesser angles of each, being each equal to a right angle, it follows that the sum of the three angles of any triangle is equal to two right angles. Thus are all of the fundamental propositions of geometry rigorously demon; strated without the aid... | |
 | University of St. Andrews - 1904 - 790 pages
...The exterior angle of a triangle is equal to the sum of the two interior and opposite angles ; and the sum of the three angles of any triangle is equal to two right angles. The three larger angles of a quadrilateral are respectively twice, four times and five times the least.... | |
 | Euclid - Euclid's Elements - 1920 - 304 pages
...the other two angles must in either case be acute. This follows from the fact (proved in i, 32) that the sum of the three angles of any triangle is equal to two right angles. i DEFINITION 22. Quadrilaterals are now classified with reference to the attributes ' equilateral '... | |
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The sum of the three angles of any triangle is equal to two right angles. 
