Sophia Learning
Sophia: Using Triangles to Find the Sum of Interior Angles: Lesson 1
This lesson demonstrates how to use triangles to determine the sum of the interior angles of a polygon. It is 1 of 5 in the series titled "Using Triangles to Find the Sum of Interior Angles."
History is Fun
Jan Brett: Geometric Shapes Flashcards Pdf
Print out these colorfully illustrated PDF file pages to practice learning your basic two dimensional geometric shapes. Fold them in half and one side shows the shape while the other side shows the shape with the correct name. Put them...