Finding the Perimeter of a Polygon on Grid Paper

This lesson teaches how to find the perimeter of a polygon using grid paper. It clarifies the difference between area and perimeter, emphasizing that perimeter measures the distance around a polygon, while area measures the space inside. The lesson explains common mistakes, such as confusing area with perimeter and counting whole square units instead of side lengths. It provides a step-by-step example of calculating perimeter by counting side lengths using hash marks, concluding with a recap of the key points.

What is a common mistake when calculating the perimeter of a polygon?

• Counting the area instead of the perimeter

• Counting the side lengths of square units

• Using hash marks to count side lengths

• Measuring the distance around the polygon

How do you find the perimeter of a polygon on grid paper?

• By counting the whole square units

• By measuring the area inside the polygon

• By counting the side lengths of the square units

• By adding the lengths of the diagonals

What tool is used to count the side lengths of square units when calculating perimeter?

• A compass

• A ruler

• Hash marks

• A protractor

In the example provided, what is the perimeter of the rectangle?

• 18 units

• 16 units

• 12 units

• 14 units

What is the final step in calculating the perimeter of a polygon using hash marks?

• Counting the number of hash marks

• Calculating the diagonal lengths

• Drawing the polygon

• Measuring the area