 | John Love - 1720 - 290 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 - 536 páginas
...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 - 288 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 - 462 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 - 476 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 - 288 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 - 582 páginas
...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 - 354 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 - 228 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 - 332 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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The three angles of any triangle are equal to two right angles — the pupil need never measure one real triangle to know this. 
