EM 4-12

EM 4-12

Rectilinear Figures

Before we start: Get out your notes and write these formulas down!

• Perimeter = add up all sides

• Area = length x width

Warm-Up

Fill in the Blank

4 x 5 = ?

Fill in the Blank

0 x 10 = ?

Fill in the Blank

3 x 9 = ?

Fill in the Blank

7 x 6 = ?

Multiple Choice

What is the perimeter of this rectangle?

• 6 cm

• 10 cm

• 5 cm

• 7 cm

Multiple Choice

What is the area of this rectangle?

• 7 inches

• 7 square inches

• 12 inches

• 12 square inches

How can we find the area of this shape?

We can decompose this shape to form two different shapes

Let's decompose!

How can we decompose this shape to find the area?

Multiple Select

Select the correct ways to decompose this shape to find area

Let's find the area of rectangle A

Area = length x width

Multiple Choice

What is the area of Rectangle A?

• 13 units

• 36 square units

• 36 units

• 13 square units

Let's find the area of rectangle B

Area = length x width

Multiple Choice

What is the area of Rectangle B?

• 10 units

• 24 units

• 20 units

• 24 square units

Let's find the area of the figure

In order to find the area of the figure, we need to add the area of Rectangle A and the area of Rectangle B

Fill in the Blank

What is the area of the entire figure? (Rectangle A + Rectangle B)

What if we don't have unit boxes?

Multiple Choice

What is the correct way to decompose this shape?

Fill in the Blank

What is the area of Rectangle A?

Look at the green ?

How many feet long is that side? (Hint: opposite sides of rectangles are the same length)

Look at the green ?

How do you think we can find the length of that side?

Fill in the Blank

What is the length of the side with the green ?

Fill in the Blank

What is the area of Rectangle B?

Let's find the area of the figure

In order to find the area of the figure, we need to add the area of Rectangle A and the area of Rectangle B

Fill in the Blank

What is the area of the entire figure? (Rectangle A + Rectangle B)

Poll

Do you understand how to decompose a shape to find area?

• YES

• NO

• Kinda, but I could use some more practice