 | Euclides - 1845 - 546 pages
...them : (xi. 4.) and EF is parallel to AB therefore AB is at right angles to the plane HGK. (xi. 8.) For the same reason, CD is likewise at right angles...to the same plane, they are parallel to one another : (xi. 6.) therefore AB is parallel to CD. Wherefore, two straight lines, &c. QED PROPOSITION X. THEOREM.... | |
 | Euclid - Geometry - 1845 - 218 pages
...through them: and t s. 11. EF is parallel to AB ; therefore AB is at right angles f to the plane HGK : For the same reason, CD is likewise at right angles...plane HGK. But if two straight lines are at right i <;. 11. angles to the same plane, they shall be parallelJ to one another; therefore AB is parallel... | |
 | Euclid, James Thomson - Geometry - 1845 - 382 pages
...sam« plane. Therefore, if three straight lines, eSzc. PROP. VI. THEOR. — If two straight lines be at right angles to the same plane, they are parallel to one another. Let the straight lines AB, CD be at right angles to the same plane BDE ; AB is parallel to CD. Let... | |
 | Euclid, John Playfair - Euclid's Elements - 1846 - 334 pages
...and EF is parallel to AB ; therefore AB is at right angles (7. 2. Sup.) to the plane — — .° HGK. For the same reason, CD is likewise at 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 are at... | |
 | Samuel Hunter Christie - 1847 - 172 pages
...them (Prop. 4): and EF is parallel to AB; therefore AB is at right angles to the plane HGK (Prop. 18). For the same reason CD is likewise at right angles...to the same plane, they are parallel to one another (Prop. 17): therefore AB is parallel to CD. Wherefore two straight lines, &c.: which was to be proved.... | |
 | John Playfair - Euclid's Elements - 1849 - 332 pages
...them : and EF is parallel to AB ; therefore AB is at right „ angles (7. 2. Sup.) to the plane HGK. For the same reason, CD is likewise at right angles...lines are at right angles to the same plane, they are paralK. -D lei (6. 2. Sup.) to one another. Therefore AB is parallel to CD. PROP. IX. THEOR. If two... | |
 | Bengal council of educ - 1852 - 348 pages
...base double of the third angle : and deduce the expression for sin 36°. 3. If two straight lines be at right angles to the same plane they are parallel to one another. 4. Chords of a circle pass through the middle point of a fixed chord, prove that the straight line... | |
 | Euclid, John Playfair - Geometry - 1853 - 336 pages
...through them : and EF is parallel to AB ; therefore AB is at right angles (7. 2. Sup.) to the plane HGK. For the same reason, CD is likewise at right angles...Therefore AB, CD are each of them at right angles H to the plane HGK. But if two straight lines are at right angles to the same plane, they are paralK.... | |
 | Euclides - 1855 - 230 pages
...therefore AB is at right angles to the plane HGK (c): for the H 0) 1.11. (6) XI. 4. (c) XI. 8. (rf) XI. 6. same reason, CD is likewise at right angles to the...to one another (d); therefore AB is parallel to CD. PROPOSITION X. THEOREM.—If two straight lines (AB, BC) meeting one another be parallel to two others... | |
 | Euclides - 1855 - 270 pages
...8) to the piano HGK. For the same reason, CD is at right angles to the plane HGK. Therefore AB Mid CD are each of them at right angles to the plane HGK. B«t if two straight lines are at right angles to the same piano, they are parallel (XL 6). Therefore... | |
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For the same reason, CD is likewise at right angles to the plane HGK. Therefore AB, CD are each of them at right angles to the plane HGK. 
