2D Shapes Worksheets for Grade 3 - mathskills4kids.com Fun accessible 2-D shapes practice for 3rd graders. Be quick to grab our 2D shapes worksheets for grade 3 with fun accessible 2-D shapes practice for 3 rd graders.These activities include: our Identify two-dimensional shapes; count and compare sides and vertices; open and closed shapes; is it a polygon?; lines, line segments, and rays; angles greater than, less than, or equal to right angle ...