 | John Playfair - 1829 - 210 pagina’s
...right angles. But they are alternate angles, therefore AB is parallel to CD. PROPOSITION III. THEOREM. Straight lines which are parallel to the same straight line are parallel to one another. Let two straight lines AB, CD be parallel to the same straight line EF; they are parallel... | |
 | Pierce Morton - 1830 - 584 pagina’s
...С : the straight lines pq, p' q1 produced, shall, each of them, pass through the point C. Because straight lines which are parallel to the same straight line are parallel to one another (IV. 6.) VC, which is parallel to PQ, is parallel also to P'Q'. But it has been already... | |
 | John Playfair - 1832 - 358 pagina’s
...since they do not meet towards L and D, they must meet if produced towards K and C. PROP. XXX. THEOR. Straight lines which are parallel to the same straight line are parallel to one another. Let AB, CD, be each of them parallel to EF; AB is also parallel to CD. Let the straight... | |
 | Euclid - 1835 - 540 pagina’s
...also BGH, GHD are equal to two right angles. Wherefore, " if a straight" &c. QED PROP. XXX. THEOR. Straight lines which are parallel to the same straight line are parallel to one another. Let AB, CD be each of them parallel to EF, AB is also parallel to CD. Let the straight... | |
 | 1835 - 684 pagina’s
...in С : the straight lines pq, p'q produced, shall, each of them, pass through the point C. Because straight lines which are parallel to the same straight line are parallel to one another (IV. 6.) VC, which is parallel to PQ, is parallel also to P'Q'. But it has been already... | |
 | 1836 - 488 pagina’s
...; and likewise the two interior angles upon the same side together equal to two right angles. XXX. Straight lines which are parallel to the same straight line are parallel to one another. XXXII. If a side of any triangle be produced, the exterior angle is equal to the two interior... | |
 | Andrew Bell - 1837 - 290 pagina’s
...do not meet towards L and D, they will meet if produced towards K. and C. PROPOSITION XXX. THEOREM. Straight lines which are parallel to the same straight line are parallel to one another. Let AB, CD, be each of them parallel to EF, ABis also parallel to CD. Let the straight... | |
 | Euclid, James Thomson - 1837 - 410 pagina’s
...same has been proved (I. 30.) respecting straight lines in the same plane : therefore, universally, straight lines which are parallel to the same straight line, are parallel to one another. PROP. X. THEOR. IF two straight lines meeting one another, be parallel to two others that... | |
 | Euclides - 1838 - 264 pagina’s
...GHD are equal* to two right angles. Wherefore, if a straight line, &c. u. E. i,. PROP. XXX. THEOR. Straight lines which are parallel to the same straight line are parallel to each other. Let AB, CD be each of them parallel to EF : AB shall be parallel to CD. Let the straight line GHK cut... | |
 | Robert Simson - 1838 - 434 pagina’s
.... Wherefore, if a straight line, &c. ft. ED * See the Notes to this Proposition. PROP. XXX. THEOR. STRAIGHT lines which are parallel to the same straight line are parallel to one another. Let AB, CD, be each of them parallel to EF. AB is also parallel to CD. Let the straight... | |
| |
Straight lines which are parallel to the same straight line are parallel to one another. Triangles and Rectilinear Figures. The sum of the angles of a triangle is equal to two right angles. 
