Answer:
Triangle (scalene)
Explanation:
Polygon is a closed figure.
The names of polygons depends on the number of sides. Some common polygons are:
3 sides - triangle
4 sides - quadrilateral
5 sides - pentagon
6 sides - hexagon
Triangle and Quadrilaterals have their own types as well.
The points G, H , and I are shown in the attached image. As you can see, it creates a 3-sided figure, which is a triangle.
Note: Since all 3 sides have different length, we call it a "scalene triangle"