GRAPHIC MATERIALS 1. GRAPHIC MATERIALS

PENCILS

PAPER

DRAWING TOOLS 2. DRAWING TOOLS

RULER We use a ruler to measure the lenght of a segment

PROTRACTOR

SET SQUARES

COMPASS This instrument is used to draw circles and arcs

geometric shapes 3. GEOMETRIC SHAPES

LINE BISECTOR The line bisector is a perpendicular line that passes through the midpoint of the segment, so it divides the segment in two equal parts.

STEPS: 1. First of all we need to draw a segment. We call it AB. 2. Center your compass in point A, open it further from the middle of the segment AB, and draw an arc. 3. Do the same from point B, where these arcs cross each other we get points 1 and 2. 4. Join 1 and 2, and this way we will get the line bisector of segment AB.

ANGLE BISECTOR

Draw a given angle Place the tip of the compass on the vertex of the angle and draw an arc which cuts each arm of the angle at two different points. Place the tip of the compass on one of the points where the first arc cuts an arm of the angle. Draw a second arc Place the compass' tip on the point of intersection of the first arc and the other arm, without changing the width of the compass. Draw a third arc which cuts the second arc at some point. Draw a line connecting the vertex of the angle and the point of intersection of the second and the third arcs.

HOW TO DRAW A TRIANGLE GIVEN THREE SIDES

Step 1:Draw the three sides of the triangle: AB, CD, EF Step 2: Draw the side AB Step 3: Set the compass width to the desired lenght CD Step 4: Move to A and draw an arc Step 5: Set the compass width to the desired lenght EF Step 6: Move to B and draw an arc

HOW TO DRAW A REGULAR HEXAGON INSIDE A CIRCLE

Step 1: draw a circle with the same radius as the side of the hexagon (AB) Step 2: Set the compass width to the desired lenght AB Step 3: Mark a point anywhere to be the first vertex of the hexagon. Step 4: with the compass on that point, draw an arc over the circle. ………

4. SKETCHES, DIAGRAMS AND PLANS 4.1. SKETCH: is a freehand drawing of the mental image we have of an object. It gives us a basic idea of what the object or the answer to a technical problem looks like.

4.2. DIAGRAM: is a more detailed representation of the idea in a sketch. It can still be a freehand drawing, but it is more accurate and gives us the measurements of the object.

4.3.TECHNICAL DRAWINGS: Includes the same information as a diagram, but is drawn using design tools so that it´s more precise. We can take measurements from it as it is drawn to scale.

NOW IT´S YOUR TURN! NOW IT´S YOUR TURN!

Draw the sketch of a chair Draw the diagram of a table

5. SCALE The scale of a drawing is the relationship between the size of the object in the drawing and the object in real life. Drawing an object to scale means enlarging or reducing all its measurements in proportion.

Ejemplo 1: 1:20 significa que 1 cm en el plano equivale a 20 cm en la realidad Ejemplo 2: 5:1 significa que 5 cm en el plano equivalen a 1 cm en la realidad.

1. Tenemos un mapa en escala 1:250000 1. Tenemos un mapa en escala 1:250000. Si la distancia entre Madrid y Barcelona es de 4 cm en el, mapa, ¿cuál es la distancia real entre estas dos ciudades? 2. Queremos dibujar una farola a escala 1:20. Si la farola mide 2 metros, ¿cuántos cm medirá en nuestro dibujo?

1.- ¿Cuál es la escala en la que está construido un mapa sabiendo que 80 km en la realidad vienen representados por 2 cm en el mapa? 2.- La escala a la que está construido un mapa es 3:700.000 ¿Cuál será la separación real existente entre dos puntos que en el mapa distan 12 cm? 3.- Dos personas se hallan separadas por una distancia de 1500m ¿Cuál sería la distancia a la que habría que dibujarlas en un mapa a escala 1:6000?

5. VIEWS OF AN OBJECT

LET´S TRY!!