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 12 Page 111

By the Vertical Angles Congruence Theorem we know that vertical angles are congruent.

x = 13
y = 20

Practice makes perfect
Looking at the figure, we can identify two pairs of vertical angles. The measure of each pair is given as algebraic expressions. One pair is written in terms of x and one pair is in terms of y. Vertical Angles 1:& 4x^(∘) and (6x-26)^(∘) Vertical Angles 2:& (6y+8)^(∘) and (7y-12)^(∘)By the Vertical Angles Congruence Theorem, we know that vertical angles are congruent. Therefore, we can equate the given expressions and solve for x and y. Let's find the value of x first.
4x = 6x-26
Solve for x
0 = 2x-26
26 = 2x
13 = x
x = 13
Now let's do the same thing for y.
7y-12 = 6y+8
Solve for y
y-12 = 8
y = 20