2. Grade 6: 2.02 Solve problems involving perimeter/ circumference and area of plane figures

3. Area is the amount of surface space that a flat object has. Area is reported in the amount of square units.

4. When you measure the amount of carpet to cover the floor of a room, you measure it in square units. Would the area of your bedroom or the area of your house be greater? You’re right! The area of your house is greater than the area of your bedroom.

5. Area = 15 square feet Lets find the area of this surface if each square is equal to one foot. Count the number of squares. 12 3 45678 91011121314 15

6. Count the number of green squares to determine the area of this surface. What is the area? The area is equal to 9 square units. Try this one! 1 5 2 4 7 3 6 89

7. Perimeter is the distance around the outside edge of a flat object. Perimeter is reported as a total number of linear units.

8. When you measure the amount of wallpaper border to go around a room, you measure it in lengths. Would the perimeter of your bedroom or the perimeter of your house be greater? You’re right! The perimeter of your house is greater than the perimeter of your bedroom.

9. Perimeter = 24 feet Let’s find the perimeter of this surface if each square is equal to one foot. Count the number of sides.

10. Count the number of sides to determine the perimeter of this flat object. The perimeter is equal to 12. Try this one!

11. Two neighbors build swimming pools. This is what the pools look like. Family A Family B Which family has the pool with the bigger swimming area? Let’s do these problems together.

12. The area of Family A’s pool is? Family A Family B 8 square units. 7 square unitsThe area of Family B’s pool is? Therefore, Family A has the pool with the bigger swimming area.

13. The perimeter of Family A’s pool is 12 units long. Family B Family A The perimeter of Family B’s pool is 14 units long. Therefore, Family B has more side panels of the pool to clean. Now look at those same two pools. Which family has more side panels of the pool to clean?

14. Calculate the Circumference Using the Correct Formula

15. Diameter = 12 cm C = Πd C = 3.14 X 12 C = 37.68 How to calculate the circumference The symbol is the Greek letter pi. It stands for a number that can never be found exactly. It is approximately 3.14 Always, write the formula (rule )

16. Diameter = ?cm d = C ÷ Π d = C ÷ 3.14 d = 40 ÷ 3.14 d = 12.73 How to calculate the diameter from the circumference If the circumference is 40 cm. evaluate the DIAMETER Always, write the formula (rule )

17. DiameterRadiusCircumference 124 214 317 430 522 6120 778 888 9120 10340 Remember d = 2 X r r = d ÷ 2

18. DiameterRadiusCircumference 1241275.36 214743.96 33417106.76 46030188.4 5221169.08 612060376.8 715678489.84 817688552.64 938.2219.11120 10108.2854.14340

19. The Circle 1.Calculate the area of a circle RADIUS The distance from the centre to the edge DIAMETER The distance from one side to the other passing through the centre Π = 3.14 (approximately) D = 2 x R and R = D ÷ 2

20. Radius = 6 A = πr 2 A = 3.14 x r x r A = 3.14 x 6 x 6 A = 113.04 cm 2 How to calculate the area Always, write the formula (rule )

21. Calculate the areas of the following circles 1 Radius = 10 cm5Diameter = 24 cm 2 Radius = 15 cm6Diameter = 21 cm 3 Radius = 13.5 cm7Diameter = 3.8 cm 4 Radius = 8.75 cm8Diameter = 12.5 cm

22. Calculate the areas of the following circles 1 314 cm 2 5452.16 cm 2 2 706.5 cm 2 6346.19 cm 2 (2 dp) 3 572.265 cm 2 711.34 cm 2 (2 dp) 4 240.41 cm 2 (2 dp)8122.66 cm 2 (2 dp)