UNIQUE FRIENDS SCHOOLSGEOMETRIC CONSTRUCTION
LINES
Geometry is the study of sizes and shapes of an object.
Geometric construction, therefore is drawing of shapes, angles or lines accurately using a compass, straight-edge (or ruler) and a pencil. An accurate geometric construction requires measurement of lines, angles and location of points. Geometric construction is fundamental to technical drawing.
LINES
A line is formed when two points are joined togther. There are many types of lines, they are;
1 Thin continuous line: This is used for drawing dimension lines, projection lines, construction lines, hatching lines, etc.
2 Thick continuous line: This is used for drawing outlines and edges.
3 Thin long chain line: This is used for drawing centre lines, pitch circles and path lines for indicating movement.
4 Thin short dash line: This is used for drawing hidden details.
5 Thick long chain line: This is used for drawing cutting planes and viewing planes.
6 Thin continuous wavy line: This is used for drawing limits of partial views or sections.
7 Thick continuous wavy line: This is used for drawing short break lines or irregular boundary lines.
8 Thin ruled with short zigzag line: This is used for drawing long break lines.
9 Arrow head line: This is used to indicate viewing planes and indicate labelled parts.