Look at the angles formed by parallel lines in the figure below:
What is the value of X?
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Look at the angles formed by parallel lines in the figure below:
What is the value of X?
Given that the three lines are parallel:
The 75 degree angle is an alternate angle with the one adjacent to angle X on the right side, and therefore is also equal to 75 degrees.
The 64 degree angle is an alternate angle with the one adjacent to angle X on the left side, and therefore is also equal to 64 degrees.
Now we can calculate:
41°
If one of two corresponding angles is a right angle, then the other angle will also be a right angle.
Alternate interior angles are on opposite sides of the transversal and between the parallel lines. They form a "Z" pattern when you trace them!
The three angles form a straight line, and angles on a straight line always sum to 180 degrees. This is true regardless of parallel lines!
Look for the parallel line symbols (arrows) in the diagram, or read the problem statement. The question will always tell you when lines are parallel!
You need to use the parallel lines property to find the unknown angles first. Without knowing that alternate interior angles are equal, you can't set up the equation .
Check that your answer is positive and less than 180° for individual angles. Also verify that exactly!
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