Elements of Geometry: With NotesJ. Souter, 1827 - 208 σελίδες |
Αναζήτηση στο βιβλίο
Αποτελέσματα 1 - 5 από τα 22.
Σελίδα 3
... distance of a point from a straight line , is meant the perpendicular from that point to the line ; and one line is said to be equi - distant from another , when every point therein is equally distant from it . 10. A plane figure is an ...
... distance of a point from a straight line , is meant the perpendicular from that point to the line ; and one line is said to be equi - distant from another , when every point therein is equally distant from it . 10. A plane figure is an ...
Σελίδα 13
... , by being produced on the side of the least distance , shall con- tinue to approach nearer and nearer to the latter , or its production , till at length it shall meet it . Let the two points F , G in the CF BOOK I. 13.
... , by being produced on the side of the least distance , shall con- tinue to approach nearer and nearer to the latter , or its production , till at length it shall meet it . Let the two points F , G in the CF BOOK I. 13.
Σελίδα 14
... distance from AB , as is manifest from the corollary to Prop . V .; still less could it , after approaching , reverse its direction , and recede from the line ABF ; for it is the obvious characteristic of a straight line to pre- serve ...
... distance from AB , as is manifest from the corollary to Prop . V .; still less could it , after approaching , reverse its direction , and recede from the line ABF ; for it is the obvious characteristic of a straight line to pre- serve ...
Σελίδα 19
... line is shorter than any other line drawn thereto from the same point ; and those lines which meet the proposed line at equal distances from the per- pendicular c 2 BOOK I. 19 PROPOSITION XX. THEOREM. (Converse of Prop. ...
... line is shorter than any other line drawn thereto from the same point ; and those lines which meet the proposed line at equal distances from the per- pendicular c 2 BOOK I. 19 PROPOSITION XX. THEOREM. (Converse of Prop. ...
Σελίδα 20
... distances DF , EF ; let also any other ob- lique line PC be drawn . A- C D F E B First , since the angle PFE is right , PE is longer than PF ( Prop . XX . Cor . 2. ) ; therefore the perpendicular is shorter than any oblique line . Again ...
... distances DF , EF ; let also any other ob- lique line PC be drawn . A- C D F E B First , since the angle PFE is right , PE is longer than PF ( Prop . XX . Cor . 2. ) ; therefore the perpendicular is shorter than any oblique line . Again ...
Άλλες εκδόσεις - Προβολή όλων
Συχνά εμφανιζόμενοι όροι και φράσεις
ABCD adjacent angles altitude angle ABC angle ACB angle BAC antecedent base centre chord circ circle circumference circumscribed polygon coincide consequently Prop construction Converse of Prop corollary demonstration described diagonals diameter divided draw enveloping line equal angles equal Prop equimultiples equivalent Euclid exterior angle follows four right angles geometry gonal greater half hence homologous sides hypothenuse hypothesis included angle inscribed angle inscribed polygon intersect isosceles triangle join Legendre less line drawn lines be drawn magnitudes meet multiple number of sides obtuse opposite angles parallel perimeter perpendicular PROBLEM proportion PROPOSITION XII quadrilateral radii rectangle rectangle contained regular polygon respectively equal rhomboid right angled triangle Scholium shorter side BC similar polygons similar triangles submultiple subtended surface tangent THEOREM three angles tiple triangle ABC vertex VIII
Δημοφιλή αποσπάσματα
Σελίδα 159 - ... if a straight line, &c. QED PROPOSITION 29. — Theorem. If a straight line fall upon two parallel straight lines, it makes the alternate angles equal to one another ; and the exterior angle equal to the interior and opposite upon the same side ; and likewise the two interior angles upon the same side together equal to two right angles.
Σελίδα 24 - If there be two straight lines, one of which is divided into any number of parts, the rectangle contained by the two straight lines is equal to the rectangles contained by the undivided line, and the several parts of the divided line. Let...
Σελίδα 80 - IF a straight line be drawn parallel to one of the sides of a triangle, it shall cut the other sides, or those produced, proportionally; and if the sides, or the sides produced, be cut proportionally, the straight line which joins the points of section shall be parallel to the remaining side of the triangle...
Σελίδα 179 - FBC ; and because the two sides AB, BD are equal to the two FB, BC, each to each, and the angle DBA equal to the angle FBC ; therefore the base AD is equal to the base FC, and the triangle ABD to the triangle FBC.
Σελίδα 136 - To describe an isosceles triangle, having each of the angles at the base double of the third angle.
Σελίδα 179 - BK, it is demonstrated that the parallelogram CL is equal to the square HC. Therefore the whole square BDEC is equal to the two squares GB, HC ; and the square BDEC is described upon the straight line BC, and the squares GB, HC upon BA, AC.
Σελίδα 99 - And since a radius drawn to the point of contact is perpendicular to the tangent, it follows that the angle included by two tangents, drawn from the same point, is bisected by a line drawn from the centre of the circle to that point ; for this line forms the hypotenuse common to two equal right angled triangles. PROP. XXXVII. THEOR. If from a point without a circle there be drawn two straight lines, one of which cuts the circle, and the other meets it ; if the rectangle...
Σελίδα 29 - In any triangle, the square of a side opposite an acute angle is equal to the sum of the squares of the other two sides diminished by twice the product of one of those sides and the projection of the other side upon it.
Σελίδα 179 - FC, and the triangle ABD to the triangle FBC. Now the parallelogram BL is double...
Σελίδα 165 - This formula already proves, that if two angles of one triangle are equal to two angles of another, the third angle of the former must also be equal to the third of the latter ; and this granted, it is easy to arrive at the theorem we have in view.