Area and Integers

1. I am creating two circular flower beds in my front yard. The 1st flower bed has a diameter of 12m the second has a radius of 8m. My front yard is 20m wide and 30m long. The rest of the front yard is grass. How many square meters of grass will I have to cut once the flower beds are in? You will have to cut 286 m2.





First Flower Bed
Ao= pi r2
Ao= 3.14 x 6 squared
Ao= 3.14 x 36
Ao= 113.04 m2

Second Flower Bed
Ao= pi r2
Ao= 3.13 x 8 squared
Ao= 3.14 x 64
Ao= 200.96 m2

The Front Yard
A= L x W
A= 30 x 20
A= 600 m2
113.04 + 200.96= 314
600 - 314= 286 m2

2. You have a triangular yard with the height of 15m and base of 10m. You build a sandbox that has a circumference of 6.28. How much of the yard is left after you build the sandbox? 71.86 m2 of the yard is left.

area=BxH/2

area=10x15/2

area=150/2

area=75m2

Ao=pi r2
Ao= 3.14 x 1 squared
Ao= 3.14 x 1
Ao= 3.14

75-3.14= 71.86 m2

Integers
Integers are positive and negative whole numbers and zero. eg. 2, -6, 91, +103, -1000, 0

NOT INTEGERS- 3/4, 1/2, 4/5, 0.1, -0.7, 91.3, 1.3, 95%, -60%

Integers are shown on a number line or using integer chips.

HOMEWORK

1. ID each integer

a . b . c ... d .... e....... f .....

2. Represent each integer with chips and/or a number line.

a) +2 b) 6 c) -4 d) +7 e) -6 f) -8