5) Constructing an Image using Lines, Circles and Polygons using GeoGebra

Constructing an Image using Lines, Circles and Polygons using GeoGebra

To recall, constructing rectangle, parallelogram and drawing triangles without any measurement has been practiced in the week 1.

Let us construct an isosceles triangle.
Open GeoGebra file and go to tool bar and select 'Circle With Centre and Radius'.

Next, click on the screen and enter the value in the box with the required measurement as radius, then click 'Ok'.

A circle appears on the screen (as shown below).



Now, construct another circle with the same radius and intersecting the previous circle.



But, to construct a triangle, we want three points.
For this, follow these steps.
Select 'Intersect'  from the toolbar.


Then, click anywhere on the two circles.

               
Select ‘Polygon’.




Draw the polygon by joining two centers and the intersecting point of the circles.












Now, to hide the circles and points from the screen,
Right click on the circle.


Uncheck 'Show object'
(then circle will get hidden from the screen).
similarly, you repeat this set of steps to hide the remaining circle and points to get the  isosceles triangle.


And, if you want to change the colour of the triangle, follow the same process which you had practiced earlier to colour the object or shape and save it.
The shape of triangle which is having all equal sides (equilateral triangle) can be drawn by following the steps, given below.

Select a point on the screen and draw a line segment beginning from it, with the required measurement.


Select ‘Regular polygon’ from the menu and drag on the line segment from left point to right endpoint of the line segment.





Give the value 3 to get a triangle.




Then, a triangle with all equal sides will appear on the screen which is an equilateral triangle.

To construct this equilateral triangle, another process can be followed as given further.


Draw a line segment with the required measurement


Then select 'Circle with radius’ from the toolbar and give the value to the radius equal to the length of the line segment drawn, as required.


Then draw the circles at two end points of the line segment with same radius equal to the length of the line segment.  Next, by selecting 'Polygon’ tool draw the polygon .



And, to get the required shape (equilateral triangle) hide all the circles and points by following those required set of steps which are already practiced. And, to change colour of the object also, follow those steps which were practiced earlier for this purpose in the Week 1.

After that just save it .

And, it’s done.