Big Ideas Math Geometry, 2014
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Big Ideas Math Geometry, 2014 View details
6. Proving Geometric Relationships
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Exercise 29 Page 114

Use the Linear Pair Postulate to form two equations in one variable.

50^(∘), 130^(∘), 50^(∘), 130^(∘)

Practice makes perfect
Looking at the figure, we can identify four pairs of supplementary angles. However, only two of these pairs are written in terms of only one variable, x or y. Supple&mentary angles: &1. 10y^(∘) and (3y+11)^(∘) &2. 10y^(∘) and (4x-22)^(∘) &3. (7x+4)^(∘) and (3y+11)^(∘) &4. (7x+4)^(∘) and (4x-22)^(∘) We will use the first and the fourth pair to find the values of y and x, respectively. By definition, the measures of supplementary angles add up to 180^(∘). We will use the first pair of supplementary angles to form the equation that can be solved for y.
10y+(3y+11)=180
Solve for y
10y+3y+11=180
13y+11=180
13y=169
y=13
Let's do the same thing for x.
(7x+4)+(4x-22)=180
Solve for x
7x+4+4x-22=180
11x-18=180
11x=198
x=18
Having solved the equations, we can calculate the individual angles by substituting x= 18 and y= 13 into the given expressions. (3* 13+11)^(∘) &=50^(∘) 10* 13^(∘) &=130^(∘) (4* 18-22)^(∘) &=50^(∘) (7* 18+4)^(∘) &=130^(∘)