Area and Perimeter Refresher

Calculating Area of 2D Shapes

Here are some of the most common area equations for various shapes.

Calculating Perimeter

Here are some of the most common perimeter equations that you may come across. To find the perimeter of any shape, all you have to do is add all of the lengths of the various sides together

Area of Irregular Polygons

To find the area of irregular polygons, break them down into smaller, regular shapes. Calculate the area of each shape using the appropriate formula (e.g., triangle, rectangle). Add up the areas of all the shapes to find the total area of the irregular polygon.

There is an example of what I mean by this on the next slide using this composite/irregular polygon

​Can you see how I took the shape and separated it into the red rectangle and the orange trapezoid? I can find the area of each shape (as shown below) then add the two values together