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3-7 Perpendicular Lines. Lines that intersect at an angle of 90 degrees are perpendicular lines. For example, let’s say that we have the. line AB. line CD. and the. A. Now, if the lines intersect at an angle of 90 o ,. C. D. then AB CD. B. Definition of Perpendicular Lines.
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Lines that intersect at an angle of 90 degrees are perpendicular lines. For example, let’s say that we have the • line AB line CD • and the A Now, if the lines intersect at an angle of 90o, C D then AB CD. B
Definition of Perpendicular Lines Perpendicular lines are lines that intersect to form a right angle. m Symbols: m n n
1 2 4 3 m n
Theorem 3-8 then they form 4 right angles. If two lines are perpendicular, a Symbols: a b 1 2 b 4 3
In the figure, and Determine whether each of the following is true or false. 7 OP MN, OP MN NP QS. QR PR P M False. Since 3 8 1 5 4 3 1 2 2 6 4 R Q True. are vertical angles, and vertical angles are congruent. N O S True. If two lines are perpendicular, then they form 4 right angles. False.