CK-12 Foundation
Area and Perimeter of Rhombuses and Kites: Lesson
Flip the triangles up and create a parallelogram. Using the idea of transformations, the video develops the area formula for rhombi and kites. The segment of an extensive geometry playlist uses the formula to find the areas of different...
CK-12 Foundation
Area and Perimeter of Trapezoids: Lesson
With a little averaging, a trapezoid becomes a parallelogram. The section of an extensive geometry playlist shows how to derive the formula for the area of a trapezoid by changing it into a parallelogram. Using the formula, the video...
CK-12 Foundation
Area and Perimeter of Similar Polygons: Lesson
Find the square of the scale factor. A component of a large playlist on geometry discusses the ratios of the perimeters and areas of two similar polygons. The resource shows examples in finding the ratios that lead to a pattern.
Math Antics
Perimeter
Discover the distance all the way around. The video introduces the concept of the perimeter of a figure. An explanation shows how to find the perimeter of a variety of polygons along with regular polygons. The presentation...
Krista King Math
Perimeter of Rectangles
Young mathematicians have been using formulas for many years, so give them extra practice with complex problems using those same formulas. Your classes apply strategies to problems that require higher order thinking. Examples include one...
Khan Academy
Khan Academy: Worked Examples: Geometry: Interesting Perimeter and Area Problems
Students explore three example problems involving perimeter and area of complex shapes.