Vertical angles are angles that are opposite each other when two lines intersect. When two angles are vertical angles, they are equal in measure.
Here are a few examples of equations involving vertical angles:
Example 1
Problem:
Line 1 intersects Line 2, creating two pairs of vertical angles. One angle measures \( 3x + 10 \) degrees, and the vertical angle measures \( 5x - 2 \) degrees. Find \( x \).
Solution: Set the two angles equal to each other: \[ 3x + 10 = 5x - 2 \]
Now, solve for \( x \):
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Subtract \( 3x \) from both sides: \[ 10 = 2x - 2 \]
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Add \( 2 \) to both sides: \[ 12 = 2x \]
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Divide by \( 2 \): \[ x = 6 \]
Example 2
Problem:
Two intersecting lines create angles of \( 2y + 15 \) degrees and \( 4y - 7 \) degrees as vertical angles. Find \( y \).
Solution: Set the angles equal: \[ 2y + 15 = 4y - 7 \]
Now, solve for \( y \):
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Subtract \( 2y \) from both sides: \[ 15 = 2y - 7 \]
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Add \( 7 \) to both sides: \[ 22 = 2y \]
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Divide by \( 2 \): \[ y = 11 \]
Example 3
Problem:
The measures of two vertical angles are given by \( 8a + 4 \) and \( 6a + 28 \). Find \( a \).
Solution: Set the angles equal to each other: \[ 8a + 4 = 6a + 28 \]
Now, solve for \( a \):
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Subtract \( 6a \) from both sides: \[ 2a + 4 = 28 \]
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Subtract \( 4 \) from both sides: \[ 2a = 24 \]
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Divide by \( 2 \): \[ a = 12 \]
Practice Problems
Now, you can try solving these equations involving vertical angles:
- \( 5x + 8 = 7x - 10 \)
- \( 4y - 5 = 2y + 15 \)
- \( 12a + 3 = 10a + 27 \)
Solutions
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For \( 5x + 8 = 7x - 10 \):
- \( 18 = 2x \), so \( x = 9 \).
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For \( 4y - 5 = 2y + 15 \):
- \( 2y = 20 \), so \( y = 10 \).
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For \( 12a + 3 = 10a + 27 \):
- \( 2a = 24 \), so \( a = 12 \).
Feel free to reach out if you have any questions or need help with more problems!