Understanding Area and Perimeter

This video is the final installment in the area and perimeter unit, focusing on finding the missing side of a rectangle when given the perimeter. The teacher reviews the concepts of area and perimeter, explains the formula for perimeter, and demonstrates how to solve for a missing side through substitution and calculation. Several example problems are worked through to reinforce the method, and students are encouraged to practice further by taking a quiz on Edmodo.

What is the definition of area?

• The width of one side of a shape.

• The measurement of the outside edge of a shape.

• The length of one side of a shape.

• The measurement of the space inside a shape.

Which operation is used to solve for perimeter?

• Multiplication

• Addition

• Subtraction

• Division

Given a rectangle with a perimeter of 24 ft and a length of 9 ft, what is the width?

• 3 ft

• 12 ft

• 6 ft

• 9 ft

If the total of both widths is 6 ft, what is the width of one side?

• 9 ft

• 12 ft

• 6 ft

• 3 ft

For a rectangle with a perimeter of 30 ft and a width of 7 ft, what is the length?

• 7 ft

• 14 ft

• 8 ft

• 16 ft

What is the first step in solving for the missing side when given the perimeter?

• Divide the perimeter by 2

• Add the known sides

• Subtract the known sides from the perimeter

• Multiply the known sides

Given a rectangle with a perimeter of 28 ft and a length of 6 ft, what is the width?

• 6 ft

• 14 ft

• 12 ft

• 8 ft

If the total of both lengths is 16 ft, what is the length of one side?

• 12 ft

• 4 ft

• 8 ft

• 16 ft

What is a shortcut for finding the missing side when given the perimeter?

• Add the known side to half the perimeter

• Divide the perimeter by 4

• Subtract the known side from half the perimeter

• Multiply the known side by 2

What should you do if you are not comfortable with shortcuts?

• Guess the answer

• Use a calculator

• Write out the formula and solve step by step

• Ask a friend for help