 | Euclid, John Keill - Geometry - 1733 - 444 pages
...in the * i*. i. Plane BH, and let AD be drawn * from the Point A perpendicular to BC ; then if AD be perpendicular to the Plane BH, the thing required is already done. But if not, let DE be drawn in the Plane from the Point D at Right Angles to BC; and let AF be drawn * from... | |
 | Robert Simson - Trigonometry - 1762 - 488 pages
...third plane, and let BD be the common fection of the firft two. BD is perpendicular to the third plane. If it be not, from the point D draw, in the plane AB, the ftraight line DE at right angles to AD the common fection of the plane AB with the third plane... | |
 | Robert Simson - Trigonometry - 1775 - 534 pages
...ftraight line BC, and from the point a i». f. A draw * AD perpendicular to BC. If then AD be alfo perpendicular to the plane BH, the thing required is already done ; but if it be not, from the bzi. i. point D draw b, in the plane BH, the ftraight line DE at right angles to BC j and from the... | |
 | Euclid - 1781 - 552 pages
...plane, and let BD be the common fection of the firft two ; BD is perpendicular to the third plane. If it be not, from the point D draw, in the plane AB, the ftraight line DE at right angles to AD the common fection of the plane AB with the third plane... | |
 | John Keill - Geometry - 1782 - 476 pages
...in the Plane BFJ; and let AD be drawn * from the Point A,»IZ.I, perpendicular to BC ; then if AD be perpendicular to the Plane BH, the Thing required is already done ; but, if not, let DE be drawn in the Plane from the* , Point D, at Right Angles to BC ; and let AF be drawn... | |
 | Euclid, John Playfair - Euclid's Elements - 1795 - 462 pages
...line BC, and from the point A draw " AD perpendicular to BC. If then AD be alfo perpendicular to-the plane BH, the thing required is already .done ; but if it be not, from the point D draw b, in the B'ane BH, the ftraight line E at right angles to BC ; and from the point A draw AF perpendicular... | |
 | Alexander Ingram - Trigonometry - 1799 - 374 pages
...ftraight line BC, and from the point a it. i. A draw » AD perpendicular to BC. If then AD be alfo perpendicular to the plane BH, the thing required...already done ; but if it be not, from the point D b ni draw b, in the plane BH, the ftraight line DE at right angles to BC ; and from the point A draw... | |
 | Robert Simson - Trigonometry - 1804 - 530 pages
...draw any ftraight line BC, and from the point A draw » AD perpendicular to BC. If then AD be alfo perpendicular to the plane BH, the thing required...already done; but if it be not, from the point D draw b A in the plane BH, the ftraight line DE at right angles to BC; and from Jfi ' the point A draw tA.F... | |
 | John Playfair, Euclid - Circle-squaring - 1804 - 468 pages
...ftraight line BC, and from the point , ,2. ,. A draw » AD perpendicular to BC. If then AD be alfo perpendicular to the plane BH, the thing required is already done ; but if it be not, from , x the point D , draw b, in the •• plane BH, the ftraight line • j£ DE alright angles to BC... | |
 | John Playfair - Mathematics - 1806 - 320 pages
...any straight line BC, and from the point A drawa AD perpendicular to BC ; then if AD be also » 12- 1 perpendicular to the plane BH the thing required is...already done. But if it be not, from . the point D drawb, in the ^ yj-A- bll. 1. plane BH, the straight line DE at right angles to BC ; and from the point... | |
| |
... plane, from a given point above it. Let A be the given point above the plane BH; it is required to draw from the point A a straight line perpendicular to the plane BH. 
