RELFE BROTHERS' EUCLID SHEETS. PROPOSITIONS 1-26, BOOK I, ARE NOW PUBLISHED IN A SIMILAR FORM TO THIS. PROPOSITION XXI. If from the ends of a side of a triangle, there be drawn two straight lines to a point within the riangle; these shall be less than the other two sides of the triangle, but shall contain a greater angle. , the ends of the side within the triangle. , let the the other two sides of the triangle, but shall contain an angle greater than the angle Produce to meet the side in Because two sides of a triangle are greater than the third side, therefore the two sides ; to each of these unequals add Again, because the exterior angle of a triangle is greater than the interior and opposite angle; therefore the exterior angle of the triangle is greater than the interior of the triangle ; for the same reason the exterior angle and opposite angle strated, that the angle the angle greater than the angle Therefore, if from the ends of the side, &c. ; and it has been demon ; much more therefore is RELFE BROTHERS' EUCLID SHEETS. PROPOSITIONS 1-26, BOOK I, ARE NOW PUBLISHED IN A SIMILAR FORM TO THIS. PROPOSITION XX. Any two sides of a triangle are greater together than the third side. Let be a triangle. Then any two sides of it together shall be greater than the third side, viz., the sides and that the greater angle is subtended by the greater side; therefore the side the angle is greater than the angle is greater than the side ; but is equal to and are greater than are greater than ; also that therefore the sides ; in the same manner it may be demonstrated, that the sides Therefore any two sides, &c. are greater than |