Activity 4 Activity 4 Polygons Polygons include any shapes constructed from segments that are simple, closed, and lie in the plane. Triangles are three-sided polygons. Triangles can be classified according to their sides and angles.
All sides have the same length.
Isosceles Two sides have the same length. All sides have different lengths. Acute All angles are less than 90 degrees. Obtuse One angle is greater than 90 degrees. One angle is 90 degrees.