2. FW 3.2: Area of a Circle Learning Target: I will find the area of a circle by estimating and squaring a circle. HW: Complete Inv. 3.2 pkt p. 6 and CORRECT with the Zaption video 3.2: Area of a Circle Warm Up: 1) Solve the equation: -3(m - 2) = 12 -3m + 6 = 12 - 6 = - 6 -3m = 6 ÷ -3 ÷ - 3 m = - 2 2) Find the circumference if the radius is 4.5 in. Formula: C = d(3.14) d = 2r C = 2(4.5) (3.14) C = 9(3.14) C = 28.26 in.

3. p. 4

5. 12 in 9 in 15 in 4.5 in 6 in 7.5 in ≈ 64 in² ≈ 113 in² ≈ 177 in² To answer this question, the owner uses scale models of the different size pizzas:

6. 12 in 9 in 15 in 4.5 in 6 in 7.5 in Approx. 64 in² Approx. 113 in² Approx. 177 in² As the diameter increases, the area increases. They are not increasing at a constant rate – as you increase the diameter by 3 inches each time, you do not increase the volume by the same amount each time (first you increase the area by about 49 inches, then you increase the area by about 64 inches). It should increase by about 81 inches to an area of 258 in². If you calculate the price based on area, then the medium pizza should be priced at (113/64)($6.00), or about $10.60. The large pizza should be priced at (177/64)($6.00), or about $16.60.

9. 6 units 36 ut² ≈ 113 ut² About 3 radius sq. 4 units 16 ut² ≈ 50 ut² About 3 radius sq. 3 units 9 ut² ≈ 28 ut² About 3 radius sq. Link to Video About Radius Squares Method

10. The area of a circle is equal to about 3 of the radius square areas. ==

11. A = Area = 3 x 8 x 8 = 192 square units

12. A fun way to remember formulas for circumference and area of a circle…

13. FW 3.2: Area of a Circle Did I reach my Learning Target? I will find the area of a circle by estimating and squaring a circle. HW: Complete Inv. 3.2 pkt p. 6 and CORRECT with the Zaption video 3.2: Area of a Circle