It seems like you're preparing for a unit test on area and perimeter from a specific lesson (Lesson 9 of Unit 5). While I can't access your specific curriculum, I can help you understand the concepts of area and perimeter and provide some practice problems.
Key Concepts:
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Perimeter:
- Definition: The perimeter is the distance around a 2D shape.
- Formula:
- Rectangle: \( P = 2(l + w) \) (where \( l \) is length and \( w \) is width)
- Square: \( P = 4s \) (where \( s \) is the side length)
- Triangle: \( P = a + b + c \) (where \( a, b, c \) are the sides of the triangle)
- Circle (Circumference): \( C = 2\pi r \) (where \( r \) is the radius)
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Area:
- Definition: The area is the amount of space inside a 2D shape.
- Formula:
- Rectangle: \( A = l \cdot w \)
- Square: \( A = s^2 \)
- Triangle: \( A = \frac{1}{2} b h \) (where \( b \) is the base and \( h \) is the height)
- Circle: \( A = \pi r^2 \)
Practice Problems:
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Perimeter Problems:
- A rectangle has a length of 10 cm and a width of 5 cm. What is its perimeter?
- A square has a side length of 8 m. What is its perimeter?
- A triangle has sides of lengths 7 cm, 4 cm, and 9 cm. What is the perimeter?
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Area Problems:
- Calculate the area of a rectangle with a length of 6 m and a width of 3 m.
- What is the area of a square whose side length is 5 cm?
- Find the area of a triangle with a base of 10 cm and a height of 5 cm.
- Determine the area of a circle with a radius of 3 m (use \(\pi \approx 3.14\)).
Sample Answers:
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Perimeter:
- Rectangle: \( P = 2(10 + 5) = 30 \) cm
- Square: \( P = 4 \times 8 = 32 \) m
- Triangle: \( P = 7 + 4 + 9 = 20 \) cm
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Area:
- Rectangle: \( A = 6 \times 3 = 18 \) m²
- Square: \( A = 5^2 = 25 \) cm²
- Triangle: \( A = \frac{1}{2} \times 10 \times 5 = 25 \) cm²
- Circle: \( A = \pi \times 3^2 = 3.14 \times 9 \approx 28.26 \) m²
Tips for Success:
- Always write down the formulas before you start solving problems.
- Double-check your arithmetic calculations.
- Pay attention to the units of measurement.
- Practice with different shapes to gain confidence.
Feel free to ask about any specific question or concept you are struggling with!