...equivalent to HH, HK, HL, therefore HA is the resultant of HK, HL. Hence, HKAL is a parallelogram ; the line joining the middle points of two sides of a triangle, is parallel to and equal to half of the third side. 3. When P is at S, the centre of the circumscribing circle ABC,...

...Exercises. 1. Triangles and parallelograms of equal bases and altitudes are respectively equal. 2. The right line joining the middle points of two sides of a triangle is | arallel to the third ; for the medians from the extremities of the base to these points will each...

...trapezoid form a quadrilateral two of whose angles are right angles. PROPOSITION XLIV. THEOREM. 130. The straight line joining the 'middle points of two...sides of a triangle is parallel to the third side and equal to one-half of it. A In the triangle ABC, let B' be the middle point of AB and C" of AC....

...— 3) ? 52. Prove that the diagonals of a square are perpendicular to each other. 53. Prove that the line joining the middle points of two sides of a triangle is parallel to the third side. 55. Show that the three points (3a, 0), (0, 3b), (a, 2li) are in a straight line. 56. Show that the...

...— 3) ? 52. Prove that the diagonals of a square are perpendicular to each other. 53. Prove that the line joining the middle points of two sides of a triangle is parallel to the thh-d side. 5.5. Show that the three points (3a, 0), (0, 3i), (a, 2K) are in a straight line. 56. Show...

...that the diagonals of a square are _L to each other. 53. Prove that the line joining the middle point of two sides of a triangle is parallel to the third side. 54. What is the geometric meaning of the equation 55. Show that the three points (3 a, 0), (0, Bb),...

...middle point of one of the sides of another piece of cardboard. Shew that their cGs are superposed. The line joining the middle points of two sides of a triangle is parallel to the third side of the triangle and is bisected by the line joining the middle point of the third side to the opposite...

...the angle, and every point not in the bisector is unequally distant from the sides. 70. Theorem. The line joining the middle points of two sides of a triangle is parallel to the third side and equal to half of the third side. 71. Theorem. A straight line drawn parallel to the base of a triangle,...

...the angle, and every point not in the bisector is unequally distant from the sides. 70. Theorem. The line joining the middle points of two sides of a triangle is parallel to the third side and equal to half of the third side. 71. Theorem. A. straight line drawn parallel to the base of a...

...one side of a triangle, parallel to a second side, bisects the third side. And, 2, the line through the middle points of two sides of a triangle is parallel to the third side. 85°. Theorem. — The three medians of a triangle pass through a common point. CF and AD are medians...