Google Classroom
GeoGebraClasse GeoGebra

Custom circular scale

How does this work ?

This applet provides a tool to draw a custom circular scale. Toggle Toolbar ImageHide/Show points and use the coloured points, sliders and Max input box to customize your scale. Ticks :
  • Max gives the largest weight on the scale, which goes from 0 to Max.
  • MajorDiv gives the number of major divisions (+1 for the 0). Your first major division will be Max/MajorDiv.
  • Use the orange triangular dot to change the length of the ticks of the major divisions.
  • MinorDiv gives you the number of intervals between two consecutive major divisions.
  • Use the pink dot to change the length of these ticks.
  • The red dot moves the position of the zero (and of the Max, symmetrically).
To position the labels :
  • Postition the blue dot to define teh radius of the circle
  • The green dot F is the center used for the rotation it should be close to the center but a bit on the left to get the central label right.
  • Point H is used to translate the second half of the labels to the left.
To position the arrow :
  • The light blue triangular dot changes the radius of the arrow and the brown triangular dot at the tip of the arrow moves on the dotted circle.
Colours, size, thickness : By using the top right menu, you can change the color of every object (ticks, text, circles, arrow) but also the width of the lines, size of points, etc. When you're done, hide the points and take a snapshot with the camera button. This will download a neat picture (file "scale.png") of the left view.
If you don't know how to use this scale with students, ask Ed Southall, not me :)