Δημοφιλή αποσπάσματα

Σελίδα 40 - LET it be granted that a straight line may be drawn from any one point to any other point.
Σελίδα 11 - A circle is a plane figure contained by one line, which is called the circumference, and is such that all straight lines drawn from a certain point within the figure to the circumference, are equal to one another.
Σελίδα 14 - A segment of a circle is the figure contained by a straight line and the circumference it cuts off.
Σελίδα 17 - When a straight line standing on another straight line, makes the adjacent angles equal to one another, each of these angles is called a right angle ; and the straight line which stands on the other is called a perpendicular to it.
Σελίδα 9 - A plane rectilineal angle is the inclination of two straight lines to one another, which meet together, but are not in the same straight line.
Σελίδα 39 - PROB. from a given point to draw a straight line equal to a given straight line. Let A be the given point, and BC the given straight line : it is required to draw from the point A a straight line equal to BC.
Σελίδα 39 - Let BAC be the given rectilineal angle, it is required to bisect it. Take any point D in AB, and from AC cut (i.
Σελίδα 30 - all right angles (for example) are equal to one another ; " that " when one straight line falling on two other straight lines makes the two interior angles on the same side less than two right angles, these two straight lines, if produced, shall meet on the side, where are the two angles less than two right angles ; " are manifestly principles which bear no analogy to such barren truisms as these, " Things that are equal to one and the same thing are equal to one another.
Σελίδα 10 - And that a circle may be described from any centre, at any distance from that centre.
Σελίδα 7 - A plane superficies is that in which any two points being taken, the straight line between them lies wholly in that superficies.