McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
5. Probabilities of Independent and Dependent Events
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Exercise 42 Page 921

Use the formula for the perimeter of a rectangle.

3

Practice makes perfect
Recall the formula for the perimeter of a rectangle. P=2l+2w ⇔ P=2(l+w) We also know that the perimeter of a rectangle is 12 and that each side length has to be an integer. P=2(l+w) and P=12 [0.3em] ⇕ [0.3em] 2(l+w)=12 Next, we can use the equation for the perimeter to find the value of the width w in terms of the length l.
2(l+w)=12
â–Ľ
Solve for w
l+w=6
w=6-l
Now, we know that the pair that satisfies the perimeter equation has a form (l, 6-l). Let's now list all possible combinations of side lengths of a rectangle, given that they are integer values!
l w=6-l (l, w) l+w? = 6
1 6- 1= 5 (1, 5) âś“
2 6- 2= 4 (2, 4) âś“
3 6- 3= 3 (3, 3) âś“
4 6- 4= 2 (4, 2) âś“
5 6- 5= 1 (5, 1) âś“
6 6- 6= 0 - *

Out of all rectangles, there are 3 that have integer side lengths and perimeter equal to 12. Thus, there are 3 possible outcomes of this situation.