1. Warm-Up 1/29 Create a vocabulary and formulas flipbook!
Use the papers on your desk and the example on the board to make a flipbook with 6 pages.
The tabs should be labeled as follows
Area
What is Area?
Square/Rectangle
All Triangles
Parallelogram/Trapezoid
Irregular Figures

2. Warm-Up /30

3. How do we find the area of different shapes?

4. Standard and Essential Question
MCC6.G.1: Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles and decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.
How do I find the area of a square and rectangle without a formula and decompose those to find the area of a triangle?

5. What do you already know about area? (Brainstorm)

6. What are the important terms?
Area: the number of square units it takes to completely fill a shape or surface.
Polygon: a two dimensional (2-D) figure made up of line segments that are connected to form a closed shape.
Quadrilateral: a four sided polygon
Vertex: the end point of two or more line segments

7. Unit Squares You can count unit squares to find the area of a figure.
Height (h)
(width)
Base (b)
(length)

8. Area= 9 square units
Base= 3 units
Height= 3 units
Area= 4.5 square units
Base= 3 units
Height= 3 units

9. Geoboard Squares Create a square that is 9 units long by 9 units wide.
Square: a quadrilateral that has 4 congruent sides and 4 right angles (90˚).
Create a square that is 9 units long by 9 units wide.
Copy that onto your dot paper!
How many unit squares make up this quadrilateral?
What is the area of the square?
What is a “shortcut”/formula to find the area?
Now put a diagonal to divide the square in half.
When you divide the square in half what two shapes do you get?
What is the area of one of those shapes?

10. Area= 12 square units
Base= 4 units
Height= 3 units
Area= 6 square units
Base= 4 units
Height= 3 units

11. Geoboard Rectangles
Rectangle: a 4-sided polygon with 4 angles that measure 90˚.
Make a rectangle that is 8 units long and 7 units wide.
Copy onto your dot paper!
How many unit squares make up this shape?
What is the area of the figure?
What is a “shortcut”/formula to find the area?
Now put a diagonal to divide the rectangle in half.
When you divide the rectangle in half what two shapes do you get?
What is the area of one of those shapes?

12. A= bh So what’s the formula?
For all rectangles and squares the formula for area is…
A= bh

13. Warm-Up /31
Stacy is planting a square garden in his backyard and needs to know how much soil to buy. One bag of soil covers 9 ft2. If the height of the garden is 14 ft., what is the area of the garden? How many bags of soil does he need?

14. Standard and Essential Question
MCC6.G.1: Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles and decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.
How are areas of geometric figures related to each other?

15. What pattern do you notice?
What about triangles?
Area of Square/Rectangle
Area of Triangle
9 units
4.5 units
12 units
6 units
14 units
16 units
What pattern do you notice?

16. Types of Triangles By Sides: By Angles:
Isosceles: a triangle that has 2 equal sides
Scalene: a triangle that has no equal sides
Equilateral: a triangle that has 3 equal sides
By Angles:
Right: a triangle with one right angle
Acute: a triangle with only acute angles
Obtuse: a triangle with one obtuse angle

17. Other Important Terms
Height of a triangle: The perpendicular distance from the base to the highest vertex.
It can be measured outside the triangle!
It can be measured inside the triangle!

18. Does the area change depending on the type of triangle?
Use the link below to determine whether the area formula of a triangle changes depending on the type of triangle.

19. How can I determine the area by only counting unit squares?

20. Let’s do some examples…
What’s the area?
What’s the area?
9.4 ft.
7 cm.
6 cm.
7 ft.
4 cm.
Area= 32.9 ft2
Area= 12 cm2

21. So what are the 2 ways to find the area of a triangle?
Compose squares and rectangles around the triangle or decompose squares and rectangles into triangles.
Use the formula: ½ bh

22. Warm-Up 2/1 Find the area of the following triangles. 1. 2. 11.7 cm.
5 m
9 m
6 cm.

23. Standard and Essential Question
MCC6.G.1: Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles and decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.
How can we use our knowledge of the area of one figure to determine the area of another?

24. Parallelogram
A quadrilateral with both pairs of opposite sides parallel
Think about it!
Do you think you can determine how to find the area of the parallelogram using the shapes we’ve already discussed?

25. How do you get the area? A=bh
A=bh
Height (h)
Base (b)

26. Let’s do some examples…
What is the area?
What is the area?
12 m
15 m
4.8 m
24 m
Area= 360 m2
Area= 57.6 m2

27. Trapezoid A quadrilateral which has one pair of parallel sides
Think about it! Do you think you can determine how to find the area of the trapezoid using the shapes we’ve already discussed?

28. How do you get the area?
Base 2 (b2)
Method #1! Get the area of both triangles and add it to the area of the rectangle.
Height (h)
Method #2!
Use the formula:
A= ½ h(b1+b2)
Base 1 (b1)

29. Let’s do some examples…
What’s the area?
What’s the area?
9 cm
10 cm
15 cm
Area= 60 m2
Area= 120 cm2

30. What is the area of the room?
Daniel has a room in his house shaped like a trapezoid. Use the picture of Daniel’s room to answer the following questions.
7 ft.
4 ft.
1 ft.
8 ft.
What is the area of the room?
If one tile can cover 1.5 square feet, how many tiles does Daniel need to cover the entire room?
32 ft.2
22 tiles

31. Warm-Up /4
A square poster board has sides that are 40 inches long. When the triangular flaps at the sides are opened, the poster board takes the shape of a trapezoid. The base of each of the triangles is 24 inches. What is the area of the trapezoid poster board?

32. Standard and Essential Question
MCC6.G.1: Find the area of right triangles, other triangles, special quadrilaterals, and polygons by composing into rectangles and decomposing into triangles and other shapes; apply these techniques in the context of solving real-world and mathematical problems.
How can you find the area of irregular polygons when you don’t have a specific formula?

33. Irregular Shapes
So how am I supposed to find the area for that?

34. Method 1: Counting Squares
Area=
18 units2

35. How can you count squares?
Hint!
Create two squares using the triangles to help find the area!
Area=
16 units2

36. Method 2: Find the area of the whole figure and then subtract the shapes that aren’t included.
Area= 111 ft2
120 ft2 – 9 ft2

37. Method 3: Find the area of the shapes separately and add their areas together.
25 mm.
12 mm.
625 mm2 (square area) mm2 (triangle area)
25 mm.
Area= 775 mm2

38. Counting Squares Challenge
Area=
38.5 units2

39. Method 2 Challenge Area= 235 ft2 15 ft. 6 ft. 4 ft. 4 ft. 11 ft. 4 ft.

40. Online Area Games Triangle Area Game
Area Explorer Game