A Practical Course in Mechanical Drawing: For Individual Study and Shop Classes, Trade and High Schools. E-book. Formato PDF William F. Willard   -  Forgotten Books, 2017  - 

For the benefit of those who, for the first time, may meet new terms and expressions in this manual, the following vocabulary, with definitions, is appended:Altitude. Vertical height.Angle. Space between two intersecting lines.Apex. Point where converging lines meet.Apices. More than one apex.Arc. Any part of the circumference of a circle.Area. Surface in units of measurement.Bisect. To cut in two equal parts.Bisector. A line which bisects.Chord. The line connecting any two points of an arc of a circle.Circumference. The boundary of a circle.Circumscribe. To draw around.Convention. Customary method or symbol used in producing a drawing.Decagon. Figure of ten sides and ten angles.Degree. One 360th part of a circle.Diameter. The distance measured across the center of a circle or a line drawn through the center terminating in the circumference.Element. A part which goes to make up the whole.Elevation. A view of an object looking at the front or side.Elliptical. Pertaining to the shape of an ellipse.Equilateral. Equal-sided.Frustum. Remaining portion of a cone or pyramid when the top has been removed parallel to the base.Hemisphere. Half a sphere.Heptagon. Figure of seven sides and seven angles.Hexagon. Figure of six sides and six angles.Horizontal. Parallel to the horizon.Hypotenuse (spelled also Hypothenuse). The diagonal distance between opposite angles of a rectangle or the side opposite the right angle.Isometric. Of equal measurement.Isosceles Triangle. A triangle with two sides of equal length and base angles equal.Lateral. Side.