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- Perimeter and Area

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Get Started Now- Intro Lesson: a6:08
- Intro Lesson: b5:37
- Intro Lesson: c9:28
- Lesson: 1a5:32
- Lesson: 1b3:27
- Lesson: 2a2:28
- Lesson: 2b2:43
- Lesson: 3a2:38
- Lesson: 3b4:12
- Lesson: 4a7:29
- Lesson: 4b4:47

In this lesson, we will learn:

- How to count areas with squares and/or triangles (unit squares and half unit squares)
- How to estimate areas of shapes on an area grid

- Review: finding
**perimeter**and**area**for**rectangular**figures

- How do you find the area of shapes that are
__not__made of squares? - If you cut a square diagonally, you will get a triangle (half a square is a triangle)

- If you cut 2 squares diagonally (2 cm
^{2}), you will get half the area (1 cm^{2}) - There are other variations of getting half of a square (1/2 cm
^{2}or 0.5 cm^{2}) - There will also be cases where you won't know the exact amount shaded in one square, but you can say whether it is more or less than half

- To
**estimate**areas of a shape on a grid, we can get close to the actual area by: - Counting all the
**whole unit squares**(fully shaded in or covered by the shape) - Counting all the
**half unit squares**(most commonly the diagonal triangle) - Rounding any squares
**shaded more than half**up to $\approx$ 1 cm^{2} - Rounding any squares
**shaded less than half**down to $\approx$ 0 cm^{2}

- IntroductionIntroduction to Calculating and Estimating Area and Perimeter:a)Estimating area for triangles (using unit squares)b)Estimating area for shaded in portions of unit squaresc)Example for estimating shaded area on a grid
- 1.
**Comparing perimeter and areas of unit square rectangles**a)Fill in the table for each rectangle with proper units (cm)b)Using the answers from part a), answer the following questions with the letter of each rectangle:- Which rectangle has the biggest perimeter? ____
- Which rectangle has the biggest area? ____
- Which rectangles have the same perimeter? ____
- Which rectangles have the same area? ____

- 2.
**Estimating the area of a shaded figure using half unit squares**

Estimate the area covered by the shaded figure.

Remember that: anda)b) - 3.
**Estimating the area of a shaded figure using halves of unit square doubles**

Estimate the area covered by the shaded figure.

Remember that: anda)b) - 4.
**Estimating the area of a shaded figure with different proportions of unit squares**

Approximate the area of the shape by filling out the table.a)How many of each type of square is shaded in?b)What is the approximate area if each square represents 1m^{2}?

The values of each type of square shaded in are listed:- whole = 1
- half =1/2
- $>$ half = 1
- $<$ half = 0