...of two sides of a triangle is parallel to the third /\ side. MA—\N \ 129. Exercise.—A straight line joining the middle points of two sides of a triangle is equal to half the third side. Hint.—Prove DE - BX, and DE = XC. 130. Defs.—A trapezoid is a quadrilateral,...

...Show that this line coincides with a line drawn / J^ as in §127. A < 129. Exercise. — A straight line joining the middle points of two sides of a triangle is equal to half the third / side. * ty— Hint.— Prove DE = BX, and DE = XC. p/ , 130. Defs. — A...

...square are of equal length, bisect each other, and are at right angles. 10. Prove analytically that the line joining the middle points of two sides of...triangle is parallel to the third side and equal to half its length. 11. Find the locus of the vertex of a triangle whose base is 2 a and the difference of...

...line parallel to AC. (Sum of A at B = 2 rt. A.) MISCELLANEOUS THEOREMS. V PROP. XL VII. THEOREM. 130. The line joining the middle points of two sides of...triangle is parallel to the third side, and equal to one-half of it. B Given line DE joining middle points of sides AB and AC, respectively, of A ABC. To...

...parallel to AC. (Sum of 4 at B = 2 rt. A.) MISCELLANEOUS THEOREMS. PROP. XLVII. THEOREM. 130. 77;e line joining the middle points of two sides of a triangle is parallel to the third side, and equal to one-half of it. B Given line DE joining middle points of sides AB and AC, respectively, of A ABC. To...

...meet in a point; 38. the perpendicular from each vertex to the opposite sides meet in a point; 39. the line joining the middle points of two sides of a triangle is parallel to the third side. 40. Show that the equation 56 z2 + 441 xy - 56 y2 - 79 x - 47 y + 9 = 0 represents the bisectors of...

...triangle whose vertices are (2, 2), (~7, -1), and (-1, 5). Plot the figure. 20. Show analytically that the line joining the middle points of two sides of a triangle is half the length of the third side. 21. A point is 7 units distant from the origin and is equidistant...

...line parallel to AC. (Sum of A at B = 2 rt. A.) A MISCELLANEOUS THEOREMS. PROP. XLVII. THEOREM. 130. The line joining the middle points of two sides of...triangle is parallel to the third side, and equal to one-half of it. Given line DE joining middle points of sides AB and AC, respectively, of A ABC. To...

...construct a rhomboid 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...

...two straight 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...