McGraw Hill Integrated II, 2012
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McGraw Hill Integrated II, 2012 View details
3. Special Right Triangles
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Exercise 59 Page 648

With an extended ratio you can express the measures of the angles with respect to the factor x.

36, 90, and 54

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 measures of the angles in a triangle with angles that fit the given extended ratio. 2 : 5 : 3 This means that we can express the measures of the angles of the triangle as 2x, 5x, and 3x.
By the Triangle Angle Sum Theorem we know that the sum of the measures of the angles of a triangle is 180. 2x+5x + 3x=180 Let's solve this equation and find x.
2x+5x+3x=180
â–Ľ
Solve for x
10x=180
x=18
Now, to find the measure of each angle of the triangle we will substitute x= 18 into the expressions for each of the angle measures.
Expression Substitute Simplify
2x 2( 18) 36
5x 5( 18) 90
3x 3( 18) 54

The measures of the angles are 36, 90, and 54.