| Robert Simson - Trigonometry - 1806 - 518 pages
...angles to the plane HGK. r~ Therefore AB, CD are each of CK n them at right angles to the plane HGK. But **if two straight lines be at right angles to the same plane, they shall be** parallel6 to one another. Therefore AB is c 6. 11. parallel to CD. Wherefore, two straight lines, &c.... | |
| John Playfair - Euclid's Elements - 1806 - 320 pages
...in one and the same plane. Therefore, if three straight lines, &c. QED j PROP. VI. THEOR. a 48. 1. f **IF two straight lines be at right angles to the same plane they** will be parallel to each other. Let the straight lines AB, CD be at right angles to the same plane... | |
| Euclid - Geometry - 1810 - 518 pages
...angles to the plane HGK. ~ Therefore AB, CD are each of ^ them at right angles to the plane HGK. But **if two straight lines be at right angles to the same plane, they shall be parallel« to one another.** Therefore AB isc6. 11. parallel to CD. Wherefore, two straight lines, &c. QED PROP. X. THEOR. IF two... | |
| Euclides - 1814 - 558 pages
...and the same plane. Therefore, if three straight PROP. VI. THEOR. if two straight lines be alright **angles to the same plane, they shall be parallel to one another. Let** them meet the plane in the points B, D, and draw the straight line BD, to which draw DE at right angles,... | |
| Euclides - 1816 - 528 pages
...BD, BE ar« in one and the same plane. Therefore, if three straight lines, 8cc. QED PROP. VI. THEOR. **IF two straight lines be at right angles to the same...lines AB, CD be at right angles to the same plane ; AB** is parallel to CD. Let them meet the plane in the points B, D, and dnlw the straight line BD, to which... | |
| John Playfair - 1819 - 317 pages
...lines, &c. Q, ED PROP. VI. THEOR. Two straight lines which are at right angles to the same plane, are **parallel to one another. Let the straight lines AB, CD be at right angles to the same plane** BDE : AB i« parallel to CD-. Draw DE at right A B I) Let them meet the plane in the points B, D. angles... | |
| Euclid, John Playfair - Circle-squaring - 1819 - 348 pages
...lines, &c. Q,. ED PROP. VI. THEOR. Two straight lines which are at right angles to the same plane, arc **parallel to one another. Let the straight lines AB, CD be at right angles to the** snme plane BDE ; AB is parallel to CD. Let them meet the plane in the points B, D. Draw DE at angles... | |
| Euclid, Robert Simson - Geometry - 1821 - 514 pages
...right angles to the plane HGK. Therefore AB, CD are each of them at right angles to the plane HGK. But **if two straight lines be at right angles to the same plane, they shall be parallel** ((?. H.) to one another. Therefore AB is parallel toCD. Wherefore, two straight lines, &c. QED i PROP.... | |
| Peter Nicholson - Mathematics - 1825 - 372 pages
...is impossible : Therefore the straight line BC is not above the plane in which are BD and PROP. VI. **THEOREM. If two straight lines be at right angles...lines AB, CD be at right angles to the same plane; AB** is parallel to CD. Let them meet the plane in the points B, D, and draw the straight line BD, to which... | |
| Robert Simson - Trigonometry - 1827 - 513 pages
...BD, BE are in one and the same plane. Therefore, if three straight lines, &c. QED PROP. VI. THEOR. **If two straight lines be at right angles to the same...AB shall be parallel to CD. Let them meet the plane** in the points B, D, and draw the straight line BD, to t u. 1. which drawf DE at right angles, in the... | |
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