Materials
An instrument that holds a lead of graphite.
Mechanical Pencil
The locus of points on a plane, equidistant from another point called the centre.
circle
Distance between any point on the circle and its centre.
radius
A geometric element which defines one direction, occupies a position in one dimension (on which length can be measured). A line is infinite.
line (straight line)
Two lines in the same plane that are at equal distance from each other and never meet.
parallel
An instrument with two arms (one arm carries a needle and the other one, a lead) joined at one end where the handle is.
Compass
Chord passing through the centre of the circle.
diameter
Two concurrent lines determine an angle, which is the plane portion comprised between them.
angle
A straight line at an angle of 90° to a given line, plane, or surface.
perpendicular
Two concurrent lines determine an angle, which is the plane portion comprised between them.
angle
They are two triangles (one has two equal sides) with certain characteristics.
Set Squares
Portion of circle between two points of it.
arc
Segment whose endpoints are two points of the circle.
chord
A tool or device used to measure length and draw straight lines.
ruler
A geometric element with a specific position but without dimensions. It’s labeled with a capital letter.
point
A ruler with millimetres and centimetres marked on the edge to measure distances.
graduated ruler
A ray is half a line. A point belonging to a line defines two rays on it; both are infinite in one way.
ray
A line portion delimited by two points.
segment
A point where two or more line segments meet.
vertex
Computer applications used to facilitate tracings in technical drawings.
digital tools
A special rubber for technical drawing, which is soft and does not smudge.
rubber
Height of an arc, measured on a line that passes through the centre of the circle and is perpendicular to the arc‘s chord.
sagitta
Indicates any path, that is not straight, closed, or open.
curve
A two-dimensional shape which has four sides of equal length.
square
A tool in a graduated semicircle shape that allows drawing
lines forming certain angles and measuring angles between lines.
angles protractor