Review Lesson: Area and Perimeter

Important Parts of a Circle

• Radius- the distance between the center of the circle and any point on the circle itself

• Diameter- the distance between any two points on a circle which crosses through the center of the circle

• Circumference- the distance around a circle

• Area- the amount of space enclosed by the circle

Circumference and Area Formulas for a Circle

Multiple Choice

Which of the following is most similar to the circumference of a circle?

• Area

• Perimeter

• Volume

• Surface Area

Multiple Select

Which of the following represents the formula for the circumference of a circle? (Select two)

• $$C=2\pi r$$
  

• $$C=\pi r$$

• $$C=\pi d$$

• $$C=2\pi d$$

Find the area and circumference of the circle

Area and Perimeter

Area

• Area is the number of square units that covers the inside of a shape.

• We can use the formula length times width (L x W) to find the area of a rectangle.

Multiple Choice

What is the area of a rectangle that has a length of 8 feet and a width of 6 feet?

• 14 squared feet

• 48 squared feet

• 40 squared feet

• 15 squared feet

A square's area formula is side times side.

A = s x s

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Multiple Choice

What is the area of the square?

• 12 sq in

• 48 in

• 24 sq in

• 144 sq in

Fill in the Blank

If a side of the square is 12 in, what is its perimeter?

Multiple Choice

What is the perimeter of a rectangle that has a length of 8 ft and a width of 6 ft?

• 14 ft

• 24 ft

• 48 ft

• 28 ft

Multiple Choice

Which measurement below has a perimeter of 18 km?

• Length = 7 km;

  Width = 7 km

• Length = 10 km;

  Width = 8 km

• Length = 2 km;

  Width = 7 km

• Length = 2 km;

  Width = 9 km

How can I find the missing side if the perimeter or area is given?

• Read the problem carefully

• Write down the information that is given.

• Use your knowledge of how to find the area and perimeter to help you solve for the missing side.

The perimeter of a shape is 36 cm. The width is 8cm. What is the length?

What do you know about a rectangle? How does that information help you solve the problem?

Place what we know in the formula.

Multiple Choice

The perimeter of a shape is 26 cm. The width is 9cm. What is the length?

• 4 cm

• 26 cm

• 8 cm

• 9 cm

Multiple Choice

The area of a shape is 36 yd. The length is 12 yd. What is the width of the shape?

• 4 yd

• 24 yd

• 3 yd

• 36 yd