Lessons on Areas and Composite Areas

Composite Area

Get your notebook (or a piece of paper) and join the Quizizz lesson from Google Classroom!

Learning Intention:

We will calculate composite area using the area formulas.

2

Success Criteria:

⦿Read the presentation slides.

⊙Vocabulary:

■Composite figure

■Composite area

⦿Discuss how to divide composite figures into basic polygons.

⦿Solve composite area problems.

Composite Area

When geometric figures are combined, the area of the resulting figure can be found by finding the individual figures' areas using the their formulas, and then adding/subtracting the results

Multiple Select

What would be a good place to split the figure in order to find the area?

What is the length of the ? side?

Multiple Choice

What is the length of the missing side?

• 2 cm

• 8 cm

• 5 cm

• 3 cm

What is the length of the ? side?

Multiple Choice

What is the length of the missing side?

• 2 cm

• 8 cm

• 5 cm

• 3 cm

Now we have all the sides. What is the area?

(Quiz on next slide)

​

​2 cm

Multiple Choice

The figure shows 2 circles inside a trapezoid.
Which procedure should be used to find the area of the shaded region?

• Subtract the perimeter of the trapezoid from the area of both circles.
• Subtract the circumference of both circles from the area of the trapezoid.
• Subtract the area of the trapezoid from the area of both circles.
• Subtract the area of both circles from the area of the trapezoid.

Multiple Choice

At a restaurant, a waiter pushed 4 identical square tables together as shown in the diagram. The width of each table is 5 feet.  Which of the following methods could the waiter use to determine the total serving area created by the 4 square tables?

• Multiply 5 by 5, then multiply the product by 4.
• Multiply 5 by 5, then multiply the product by 5.
• Add 4 plus 4, then multiply the sum by 5.
• Multiply 4 by 5, then add 4 to the product.

Some examples...

Copy these examples into your notebook or a piece of paper.

Multiple Choice

What is the area of the shaded region?

• 98.7 cm²

• 119.3 cm²

• 122.4 cm²

• 158.5 cm²

Multiple Choice

What is the area of the shaded region?

• 625
• 134.375
• 490.87
• 228.4

Multiple Choice

Determine the area of the composite figure shown below.

• 168 centimeters squared 
• 98 centimeters squared 
• 84 centimeters squared 
• 70 centimeters

Your turn!

We have some quiz questions coming up! Get ready! You might want a piece of paper to write your work on. You will have 2 minutes for each question.

Multiple Choice

What is the area of the shaded region?

• 20 sq cm
• 4 sq cm
• 30 sq cm
• 24 sq cm

Multiple Choice

What is the area of the shaded region?

• 23.1 cm²

• 5.1 cm²

• 17.4 cm²

• 37.3 cm²

Multiple Choice

What is the area of the shaded region?

• 16 cm²

• 12.9 cm²

• 22.4 cm²

• 15.8 cm²

Multiple Choice

Find the composite area.

• 6.28

• 24

• 40

• 38.28

Multiple Choice

What is the area of the shaded region?

• 47 cm²

• 122 cm²

• 32 cm²

• 60 cm²