The three angles of any triangle are equal to two right angles — the pupil need never measure one real triangle to know this. Circular of Information - Página 129por United States. Bureau of Education, United States. Office of Education - 1889Vista completa - Acerca de este libro
| John Love - 1720 - 196 páginas
...great as 90 Degrees ; or which confifts of two Acute Angles and one Obtufe •viz. at that D. 3. All **the three Angles of any Triangle are equal to two Right Angles,** or 1 80 Degrees $ k> that one Angle being known, the other two together are known a lib; or two being... | |
| John Leng (bp. of Norwich.) - 1730
...Mathematicks, upon viewing a great variety of Triangles and other figures, fhould take a fancy to deny that **the three angles of any triangle are equal to two right angles,** or to the three angles of any other triangle}beca.ufe he will not give himfelf the trouble of confidering... | |
| John Love - 1744 - 207 páginas
...great as 90 Degrees; or which confifts of two Af cute Angles and one Obtufe, viz. as that D» , 5. All **the three Angles of any Triangle are equal to two Right Angles,** or .., 1 80 Degrees ; fci that One Angle being known, tne other two together are known alfo ; or two.be1hg... | |
| John Keill - 1772 - 399 páginas
...I fay, two oppofite Angles thereof are equal to two Right Angles. For join AD, BC. \ Then, becaufe **the three Angles of any Triangle are * equal to two Right Angles, the** three Angles of the* 3Z- Tt Triangle ABC, viz. the Angles CAB, ABC, BCA, are equal to two Right Angles.... | |
| John Keill - 1782 - 399 páginas
...D. I fay, two oppofite Angles thereof are equal to two Right Angles. F»rjoin AD, B C. Then, becaufe **the three Angles of any Triangle are * equal to two Right Angles, the** three Angles of the * aZl '• Triangle ABC, viz. the Angles CAB, ABC, BC A, are equal to-two Right... | |
| John Love - 1792 - 206 páginas
...90 degrees ; or as C, which con'f1fts of two acute angles and one obt1ife, viz, that at "d.> 3. All **the three angles of any triangle are equal to two 'right angles,** or 180 degrees; fo that one angle being known, the fiirri of the other two becomes known alfo ., or... | |
| Charles Butler - 1814
...rad.— log. AB ; whence the angle B is found, both by natural numbers and logarithms. Lastly, since **the three angles of any triangle are equal to two right angles** (32. 1.) =180", and the angle C (a right angle) = 90", v B+A= (180>-C=lS<r— 90°=) 90°; but the... | |
| John Playfair - 1819 - 317 páginas
...each to each, the third angles are also equal. Now, this being demonstrated, it is easy to prove that **the three angles of any triangle are equal to two right angles.** Let ABC be a triangle right angled at A, draw AD perpendicular to BC. The triangles ABD, ABC have the... | |
| John Radford Young - 1827 - 208 páginas
...Therefore the three angles of a triangle cannot be greater than two right angles. PROPOSITION III. **The three angles of any triangle are equal to two right angles.** If what is affirmed be not true, let the three angles of the triangle ACB be less than two right angles,... | |
| John Playfair - 1837 - 318 páginas
...each to each, the third angles are also equal. Now, this being demonstrated, it is easy to prove that **the three angles of any triangle are equal to two right angles.** Let ABC be a triangle right angled at A, draw AD perpendicular to BC. The triangles ABD, ABC have the... | |
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