 Thus when it is said that the sum of the three angles of any triangle is equal to two right angles, this is a theorem, the truth of which is demonstrated by Geometry.  Elements of Mechanical Drawing - Page 22by Gardner Chace Anthony - 1894 - 98 pagesFull view - About this book
 | Connecticut. Board of Education - 1885 - 306 pages
...sphere is measured by the circumference of one of its great circles multiplied by its diameter. IL 1. The sum of the three angles of any triangle is equal to two right angles. 2. If a straight line is divided into any two parts, the square described on the whole line is equivalent... | |
 | William Chauvenet, William Elwood Byerly - Geometry - 1887 - 331 pages
...interior angles on the same side of the secant line is equal to two right angles. PROPOSITION XXVI. The sum of the three angles of any triangle is equal to two right angles. Corollary. If one side of a triangle is extended, the exterior angle is equal to the sum of the two... | |
 | Joseph Baldwin - Educational psychology - 1887 - 334 pages
...three angles of this triangle is equal to two right angles ; But this is a typical triangle ; .•. The sum of the three angles of any triangle is equal to two right angles. (Give two examples, and show that a single typical case justifies a general conclusion.) 2. Deductive... | |
 | George Johnston Allman - Geometry - 1889 - 266 pages
...Further, since any triangle can be resolved into two right-angled triangles, it follows immediately that the sum of the three angles of any triangle is equal to two right angles. If, then, we accept the evidence of Pamphila as satisfactory, we are forced to the conclusion that... | |
 | Jonathan Rigdon - English language - 1890 - 302 pages
...sentences ; but "Columbus believed that the earth is a sphere," and " Some old mathematician proved that the sum of the three angles of any triangle is equal to two right angles," can not claim to be more than elegant examples of false syntax, notwithstanding the sanction of nearly... | |
 | Edward Albert Bowser - Geometry - 1890 - 418 pages
...BC, (Ax. 10) Taking AC from each, AB - AC < BC, or BC > AB - AC. QED A Proposition 2O. Theorem. 97. The sum of the three angles of any triangle is equal to two right angles. Hyp. Let ABC be any A . To prove Proof. Produce AB to D, and draw BE || to AC. AB ° Then since BE... | |
 | Edward Albert Bowser - Geometry - 1890 - 420 pages
...(Ax. 10) Taking AC from each, AB - AC < BC, or BC > AB - AC. QED A Proposition 2O. Theorem. 97. TJie sum of the three angles of any triangle is equal to two right angles. Hyp. Let ABC be any A . To prove ZA + Z ABC + ZC = 2 rt. Z s. Proof. Produce AB to D, and draw BE ||... | |
 | William Chauvenet - 1893 - 340 pages
...perpendicular to one of two parallel lines is perpendicular to the other. PROPOSITION XXVI.—THEOREM. 50. The sum of the three angles of any triangle is equal to two right angles. Let ABC be any triangle; then the sum of its three angles is equal to two right angles. Produce BC,... | |
 | Rutgers University. College of Agriculture - 1893 - 680 pages
...carpet a meter in width is required to carpet a room 4.2 meters long and 3.8 meters wide ? GEOMETRY. 1. The sum of the three angles of any triangle is equal to two right angles. 2. An inscribed angle is measured by one-half the arc intercepted between its sides. 3. The perimeters... | |
 | University of the State of New York. Examination Department - Examinations - 1894 - 412 pages
...relation existing between the segments of two chords which intersect within a circle. 8 Prove that the sum of the three angles of any triangle is equal to two right angles. 9 What is the measure of an inscribed angle ? Prove the correctness of your answer. 10 Show how the... | |
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