McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
1. Ratios and Proportions
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Exercise 15 Page 546

With an extended ratio you can express the lengths of the sides with respect to the factor x.

2.2 ft

Practice makes perfect
An extended ratio compares three or more numbers. In an extended ratio a : b : c, the ratio of the first two numbers is a : b, the ratio of the last two numbers is b : c, and the ratio of the first and last numbers is a : c. We want to find the length of the longest side in a triangle with sides that fit the given extended ratio. 1/4 : 1/8 : 1/6 This means that we can express the lengths of the sides of the triangle as 14x, 18x, and 16x.
We know that the perimeter of the triangle is 4.75 feet. Therefore, the sum of the side lengths of the triangle is 4.75. 1/4x + 1/8x + 1/6x=4.75 Let's solve this equation and find x.
1/4x+1/8x+1/6x=4.75
Solve for x
24/4x+24/8x+24/6x=114
6x+3x+4x=114
13x=114
x=114/13
x ≈ 8.77
Now, to find the length of each side of the triangle we will substitute x ≈ 8.77 into the expressions for each of the side lengths.
Expression Substitute Simplify
1/4x 1/4 ( 8.77 ) 2.2
1/8x 1/8 ( 8.77 ) 1.1
1/6x 1/6 ( 8.77 ) 1.46

As we can see, the length of the longest side is 2.2 feet.