| Association for the improvement of geometrical teaching - Geometry, Modern - 1884 - 150 pages
...first pair are respectively equal to the angles made by the second pair. THEOR. 24. Straight lines that **are parallel to the same straight line are parallel to one another.** Let the straight lines AB, CD be each parallel to the straight line EF : then shall AB and CD be parallel.... | |
| James Maurice Wilson - Conic sections - 1885 - 180 pages
...perpendicular by the first part of theTheorem : therefore the perpendicular is the parallel. THEOREM 8. **Straight lines which are parallel to the same straight line are parallel to one another** '. Let A and B be each of them parallel to C; then shall A be parallel to B. Proof. Take a plane PQ... | |
| Canada. Department of the Interior - 1888 - 756 pages
...every triangle is subtended by the greater side, or, has the greater side oppdsite to it. 2. Show that **straight lines which are parallel to the same straight line are parallel to** each other. 3. Show that if a straight line be divided into two equal parts, and also into two unequal... | |
| George William Usill - Surveying - 1889 - 306 pages
...one another, and also the exterior angle equal to the interior and opposite upon the same side. 17. **Straight lines which are parallel to the same straight line are parallel to one another.** 18. If a side of any triangle B c be produced to D, the exterior angle is equal to the two interior... | |
| Edward Mann Langley, W. Seys Phillips - 1890 - 538 pages
...made in the above enunciation if we substitute right for acute or obtuse ? PROPOSITION 30. THEOREM. **Straight lines which are parallel to the same straight line are parallel to one another.** Let AB, CD be each of them || to EF; then AB shall be || to CD. Let st. line GH K cut the ||s AB, EF,... | |
| Edward Albert Bowser - Geometry - 1890 - 418 pages
...(Ax. 3) And these being alternate Z s, . • . AB || to CD. (75) QED Proposition 1 6. Theorem. 79. **Straight lines which are parallel to the same straight line are parallel to one another.** Hyp. Let the st. lines AB, CD A EX- B be each || to the st. line PQ. ^ /- ^ To prove AB || to CD. -r... | |
| Euclid - Geometry - 1890 - 442 pages
...+ BSR = ASR + BSR, = two rt. A 8. AA Similarly SRC + ASR = two rt. A". Proposition 30. THEOREM — **Straight lines which are parallel to the same straight line are parallel to** each otfier. Let st. lines AB, CD be each || to PQ. Draw XY across them, meeting AB, PQ, CD in _ f... | |
| Rupert Deakin - Euclid's Elements - 1891 - 102 pages
...same side ; and also the two interior angles on the same side together equal to two right angles. 30. **Straight lines which are parallel to the same straight line are parallel to one another.** 31. To draw a straight line through a given point parallel to a given straight line. 32. If a side... | |
| James Andrew Blaikie, William Thomson - Geometry - 1891 - 154 pages
...the two interior angles on the same side of the cutting line together equal to two right angles. 30. **Straight lines which are parallel to the same straight line are parallel to** each other. 31. Through a given point, to draw a straight line parallel to a given straight line. 32.... | |
| Euclid, John Bascombe Lock - Euclid's Elements - 1892 - 184 pages
...either of the lines making the angle, the triangle thus formed will be isosceles. Proposition 30. 116. **Straight lines which are parallel to the same straight line are parallel to one another.** Let the straight lines EF, GH be each parallel to KL, it is required to prove that EF, GH are parallel... | |
| |