The elements of Euclid for the use of schools and colleges; comprising the first six books and portions of the eleventh and twelfth books; (1903)
Euclid, Todhunter, I. (Isaac), 1820-1884, ed. edt, Simson, Robert, 1687-1768, ed. edt · London; New York, Macmillan · leaf 306
second straight line. ##2. If the perpendiculars drawn from two points to a plane beequal, the straight line joining the two points is parallel to the plane. 294 EUCLIDS ELEMENTS. Proposition 8. Theorem. If two straight lines he parallel, and one of them he at rightangles to a plane, the other also… … Construction. Let AB, CD meet the plane at the pointsB, D; join BD; then AB, CD, BD are in one plane. [XL 7.In the plane to which AB is at right angles, draw DE atright angles to BD ; [I. 11. make DE equal to AB; and join BE, AE, AD. Proof. (1) Because AB is at right angles to the plane, [Hyp.it is…
Euclid's Elements · Geometry · Mathematics, Greek
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