Books Books The straight line joining the middle points of two sides of a triangle is parallel to the third side and equal to half of it 46 INTERCEPTS BY PARALLEL LINES. Euclid - Page 99
by Euclid, Rupert Deakin - 1903 - 164 pages ## The Elements of Plane Geometry

Charles Austin Hobbs - Geometry, Plane - 1899 - 266 pages
...when the two diagonals and the included angle are given. Proposition 64. Theorem. 76. The line joining the middle points of two sides of a triangle is parallel to the third side, and is equal to one half the third side. B 57 Conclusion. DE is II to BC, and DE = \ BC. Proof. Draw CF... ## Plane Geometry

William James Milne - Geometry, Modern - 1899 - 258 pages
...lines drawn between the same two points, which by Ax. 12 is impossible. Consequently, the line joining the middle points of two sides of a triangle is parallel to the third side. Proposition XLIII 160. Draw a trapezoid and a line connecting the middle points of the non-parallel... ## Plane and Solid Geometry

William James Milne - Geometry - 1899 - 404 pages
...lines drawn between the same two points, which by Ax. 12 is impossible. Consequently, the line joining the middle points of two sides of a triangle is parallel to the third side. Proposition XLIII 160. Draw a trapezoid and a line connecting the middle points of the non-parallel... ## New Plane and Solid Geometry

Wooster Woodruff Beman, David Eugene Smith - Geometry - 1899 - 412 pages
...Draw a third parallel through the vertex. Then cor. 1 proves it. 3. The line joining the mid-points of two sides of a triangle is parallel to the third side. For if not, suppose through the mid-point of one of those sides a line is drawn parallel to the base... ## New Plane Geometry

Wooster Woodruff Beman, David Eugene Smith - Geometry, Modern - 1899 - 272 pages
...of a triangle, parallel to another side, bisects the third side. 3. The line joining the mid-points of two sides of a triangle is parallel to the third side. For if not, suppose through the mid-point of one of those sides a line is drawn parallel to the base;... ## Plane and Solid Analytic Geometry: An Elementary Textbook

Charles Hamilton Ashton - Geometry, Analytic - 1902 - 310 pages
...on a line, and find the ratio of their distances from each other. 7410. Show that the line joining the middle points of two sides of a triangle is parallel to the third side and equal to one half of it 11. Show that the diagonals of a square or rhombus are perpendicular to each other.... ## Pure Mathematics 2

Linda Bostock, Suzanne Chandler, F. S. Chandler - Algebra - 1979 - 660 pages
...In Questions 1—8 give proofs based on vector methods. 1) Prove that the line joining the midpoints of two sides of a triangle is parallel to the third side and equal to half of it. 2) Prove that the internal bisectors of the angles of a triangle are concurrent. 3) Prove that the... ## Great Moments in Mathematics (before 1650)

Howard Whitley Eves - Mathematics - 1983 - 292 pages
...FM, EN. Then FE is parallel to BC and equal to one-half of BC (the line segment joining the midpoints of two sides of a triangle is parallel to the third side and is equal to one-half the third side). Similarly, MN is parallel to BC and is equal to one-half of BC.... ## The Foundations of Geometry and the Non-Euclidean Plane

G.E. Martin - Mathematics - 1997 - 536 pages
...quadrilaterals in absolute geometry are contained in Theorem 22.4. • 22.16 The line through the midpoints of two sides of a triangle is parallel to the third side. 22.17 Theorem 22.17 could have followed Definition 21.9. Why didn't it? Would this rearrangement have... 