Watch the video below which is all about polygons. Polygons are 2D shapes with 3 or more straight sides. All quadrilaterals are polygons, but there are other types of polygons too. As you can see ...

Quadrilaterals close quadrilateralA polygon ... divide the sum of interior angles in a triangle by 3 In an isosceles triangle, two of the sides are equal. This means two of the angles are equal.