Presentation on theme: "Yolanda López ESO 1 - TECHNOLOGIES. WHAT IS IT? A scale drawing represents something that is: too large to be drawn to actual size OR too small to."— Presentation transcript:
Yolanda López ESO 1 - TECHNOLOGIES
WHAT IS IT? A scale drawing represents something that is: too large to be drawn to actual size OR too small to be drawn to actual size
In other words, a scale drawing is eitherthe reduction or enlargement o f an object.
Because we want the drawings to fit on a standard size piece of paper.
Each scale drawing has a scale. The scale is the ratio that compares the length of the drawing to the actual object.
1:1 ONE TO ONE, FULL SIZE, OR LIFE- SIZED DRAWINGS This means that 1cm on the paper is equal to an actual distance of 1cm. You draw something in the same size it would be in real life. e.g. a CD case
1:2 This means your drawing is half size of the original object. 1 cm on the drawing would be equal to 2 cm in real life. Which one is the original object? Why?
2:1 2cm on the drawing equal 1 cm in real life. This means the actual object is half size of the drawing.
Match 1:1DOUBLE SIZEThe drawing is the exact same size as the actual object 1:2HALF SIZEThe drawing is half the size of the artifact 2:1FULL SIZEThe drawing is twice as large as the artifact
Decide wether to enlarge or reduce these objects: A cellphone A marble A lion A salt crystal A killer whale An eraser A glue stick A knife A sofa A dragonfly Eiffel tower Rocket Full size Enlargement Reduction Enlargement Reduction Enlargement Full size Reduction Enlargement Reduction
Let’s make a scale drawing: http://www.pcastela.es/recursos/oxford_dibujo/ _media/menuppal.html HINT Multiply the length by the scale factor 1:2 scale factor = 0.5 2:1 scale factor = 2