Khan Academy
Khan Academy: Geometry: Challenging Perimeter Problem
Demonstrates how to solve a problem from the 2000 American Invitational Mathematics Examination which involves finding the perimeter of a rectangle covered by nine overlapping squares. [9:56]
Khan Academy
Khan Academy: Geometry: Area and Perimeter
Explains how to calculate the area of rectangles, squares, and triangles, in addition to the perimeter of rectangles and squares. Practice problems available. [12:20]
CK-12 Foundation
Ck 12: Elem Math: Overview of Area and Perimeter of Squares
[Free Registration/Login may be required to access all resource tools.] Students watch a video overview on how to find the area and perimeter of squares.
Art of Problem Solving
Art of Problem Solving: Funky Area
Video tutorial shows how to calculate the area around a circle that is inside a square. [4:22]