## Tuesday, November 20, 2012

### Textbook Pg. 79, #17

My Question:

Some parks contain fenced gardens. Suppose that it costs \$80 to build each metre of fence, including materials and labour.

a) How much does it cost to enclose a square with an area of 120 m²? Express your answer to the nearest dollar.

b) Predict whether the total cost of enclosing two squares with an area of 60 m² each is the same as your answer for part a).

part a) The first step is trying to find the square root of 120 by using a calculator. The square root is also the same value as one side of the square garden.

√120 = 10.95

Because there are 4 sides in a square, you need to multiply 10.95 by 4.

10.95  x 4 = 43.8

Then, you need to multiply the number above by \$80 to the the final answer.

43.8 x \$80 = \$3504

The cost of enclosing a square with an area of 120 m² is \$3504

part b) Following the same procedure we used for part a), find the square root of one square with an area of 60 m²

√60 = 7.74

7.74 x 4 = 30.96

30.96 x 80 = 2476.8

And because we are finding the area of two 60 m² fenced gardens, multiply that previous answer by two.

2476.8 x 2 = \$4953.6

As you can see, the results are Not The Same.

c) I predicted that the costs for the fenced gardens would not be the same because two 60 m² squares have a total of 8 sides, and a 120 m² only has four sides, therefore I knew that the area would of the 60 m² would be larger because of the greater amount of sides.