Today in class students worked on the area of circles on a grid by counting the full grid squares and estimating the partial ones.
Answers to HW: 1. The first graph shows the relationship between the diameter and area of a circle, because it is not a proportional relationship. The second graph shows the relationship between the diameter and the radius, because it is proportional and the constant of proportionality is 12. The third graph shows the relationship between the diameter and the circumference, because is it proportional and the constant of proportionality is π. 2. a. The square inside the circle has an area of 2 square units because it is made of 4 triangles each with area 1/2 square unit, and 4/2 = 2. The square outside the circle has an area of 4 square units, because 2 squared = 4. b. The square inside the circle has an area of 18 square units because 12 + 12/2 = 18 (the square inside the circle contains 12 full grid squares and 12 half grid squares). The square outside the circle has an area of 36 square units because 6 squared = 36. 3. About 4,500 in. squared If the diameter is 3 times greater, the area must be 3 squared, or 9 times greater. 4. About 1.82 meters because 100 ÷ 55 ≈ 1.82 5. About 47 cm because 15 ⋅ π ≈ 47 6. 75 cm
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
October 2018
Categories |