Area and Perimeter Refresher

Exploring Shapes:

Understanding area, perimeter, and volume

Calculating Area of 2D Shapes

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

Multiple Choice

Which formula should be used to calculate the area of a rectangle?

• Multiply the length by the width

• Multiply the base by the height and divide by 2

• Multiply the radius squared by π

• Break the shape into smaller, simpler shapes and calculate their areas separately

Math Response

What is the area of this triangle?

Round to 1 decimal place

Type answer here

Correct Answer: 206.5

Deg^°

Rad

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

Multiple Choice

What is the formula to calculate the perimeter of a rectangle?

• Perimeter = Length + Width

• Perimeter = 2L + 2W

• Perimeter = Length * Width

• Perimeter = 2 * Length

Math Response

What is the perimeter of this trapezoid?

Type answer here

Correct Answer: 74

Deg^°

Rad

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

Math Response

What is the area of this composite shape?

Type answer here

Correct Answer: 66

Deg^°

Rad