DRAFTING

• Two sources of beauty are commonly recognized-- nature and art
• Horizontal lines are lines parallel to the lower edge of the drawing paper
• Vertical lines are sketched from top downward
• Inclined lines are sketched from left to right
• short line are drawn with finger movement
• long lines are made with arm movement, but can be drawn in segments with very small spaced or gaps between segments
• horizontal lines are drawn from left to right
• perpendicular lines are lines which make an angle of 90 degrees
• Horizontal and vertical lines can be drawn perpendicular to one another
• Not all perpendicular lines are vertical or horizontal
• Parallel lines never meet and can be vertical, horizontal or inclined
• A regular curve is either a circle, an arc, or an ellipse
• Irregular curves have no definite direction
• Soft pencils range from grades B, 2B, ....., to 6B (the softest)
• Between H and B pencils are the HB and F.
• With HB, 2B, and H pencils, the student can easily make variation in the lightness or darkness of his lines even if the pressure of the pencil on the paper is the same for each grade pencil
• The pencil points may be sharpened into three different shapes: conical, chisel, and elliptical. The conical and chisel are recommended for sketching
• The conical pointed soft pencil can make different thicknesses of lines by varying the pressure of the pencil against the paper surface.
• A hard pencil with a similar point can make different thicknesses of lines by varying the shape of its point
• The chisel point makes wide lines depending on the width of the point. It is generally used in shading a penciled outline drawing
• All geometrical figures are imaginary or invisible
• A line is the movement of a point and the latter only indicates position
• A quadrilateral is a plane figure with foure sides. Some are the trapezoid, square, rectangle, and parallelogram
• A parallelogram is a quadrilateral with two opposite sides parallel and equal. examples are square, rhombus, and rectangle
• A trapezoid is a quadrilateral with two opposite sides parallel
• A trapezium is a quadrilateral but has no equal sides and angles
• The right triangle has an angle of 90 degrees
• The equilateral angle has equal sides and angles
• The isosceles triangle has two sides equal
• The scalene triangle has none of its siddes equal
• A rectangle is sometimes called oblong, and an oval is egg-shaped
• Two or more circles with a common center are concentric circles while those without a common center are called eccentric circle
• An ellipse is a plane figure bounded by a curved line but without a common center. It has a major diameter and a minor diameter
• A cone is a geometrical solid with a circular base and with sides tapering to a point, called a vertex
• If a cone is cut parallel to its base, the bottom art is called a frustum of the cone and the upper part is a smaller cone
• If the cutting plane is oblique or inclined, the resulting cone is truncated
• A pyramid is a solid figure the base of which is either a square, triangular, rectangular, or polygonal in shape
• A prism is a solid figure with a base either a square, rectangular, or polygonal in shape
• If the other five sides of a square prism are equal in size with the base, the figure is called a cube
• A cylinder has a circular base, and its sides are either vertical or inclined