Circle Area Worksheet A Worksheets are moreless structured

Circle – Area – Worksheet A Worksheets are more/less structured and in two sizes.

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How can we estimate the area of the circle?

How can we estimate the area of the circle? 9 units 2

Area of the square = 2 cm Area of the circle ≈

Area of the square = Area of the circle = 2 cm This is Pi, π Instead of multiplying by 4 to get the area of the square, We multiply by 3. 14. . 3. 1415926535897932384626433832795028841971…

Discovering the Area of a Circle Part A 1) Estimate the area of the shaded shape. (Hint: Use rectangles, then estimate the remaining pieces. ) 2) Calculate the area of each square. 3) What fraction of the square is shaded? ① Your estimate for the shaded fraction ➜ Shaded Area ≈ 16 units 2 Shaded Area ≈ 78 units 2 Shaded Area ≈ 310 units 2 Square Area = 36 units 2 Square Area = 100 units 2 Square Area = 400 units 2 Part B 1) Calculate the area of each square. 2) Use your answer from Part A to calculate the area of each circle. 2 cm Area = 16 cm 2 Area ≈ 12 cm 2 3 cm Area = 36 cm 2 Area ≈ 27 cm 2 5 cm 3 cm Area = 100 cm 2 Part C Area ≈ 75 cm 2 You now have a formula for the area of a circle! Use the formula to find the area of this circle. 6 cm Express the area of this square. Express the area of the circle using the fraction. Simplify the expression. Area ≈ 108 cm 2

Part A What fraction is the area of the circle compared to the total square? Part B Discovering the Area of a Circle Part C 6 cm Calculate the area of the square. Use your answer from Part A to calculate the area of the circle. With algebra, write an expression for the area of the square. Use your fraction from Part A to write an expression for the area of the circle. ②

Discovering the Area of a Circle Part A 1) Estimate the area of the shaded shape. (Hint: Use rectangles, then estimate the remaining pieces. ) 2) Calculate the area of each square. 3) What fraction of the square is shaded? ① Your estimate for the shaded fraction ➜ Shaded Area ≈ 16 units 2 Shaded Area ≈ 78 units 2 Shaded Area ≈ 310 units 2 Square Area = 36 units 2 Square Area = 10 units 2 Square Area = 400 units 2 Part B 1) Calculate the area of each square. 2) Use your answer from Part A to calculate the area of each circle. 2 cm Area = 16 cm 2 Area ≈ 12 cm 2 3 cm Area = 36 cm 2 Area ≈ 27 cm 2 5 cm 3 cm Area = 100 cm 2 Part C Area ≈ 75 cm 2 You now have a formula for the area of a circle! Use the formula to find the area of this circle. 6 cm Express the area of this square. Express the area of the circle using the fraction. Simplify the expression. Area ≈ 108 cm 2

Part A What fraction is the area of the circle compared to the total square? Part B Discovering the Area of a Circle Part C 6 cm Calculate the area of the square. Use your answer from Part A to calculate the area of the circle. With algebra, write an expression for the area of the square. Use your fraction from Part A to write an expression for the area of the circle. ②

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