Centroid
Steps of Construction:
Use polygon tool to make a triangle.
Use mid-point tool to get the mid-points of the sides.
Draw line segment between each of the three vertices and the mid-points on the opposite sides.
Using intersecting tool to get the intersecting point of the line segments.
The line segemnts are concurent and their point of intersection is the centroid.
Use other GeoGebra tools to get the centroid. Try out different ways to get the centroid.