Two lines are parallel if they never meet. So, for example, the lines and below are parallel.
If two lines are parallel, we can express this using the symbol as follows:
In words, we say, "the line is parallel to the line "
If two lines are not parallel, they must have a common point. In this case, we say that the lines intersect.
For example, the lines and below intersect at the point
We have the following important property about lines in two-dimensional space.
Any two distinct lines are either parallel or intersect at exactly one point.
List all of the parallel lines in the diagram below.
Two lines are parallel if they never intersect.
In the given diagram, the only parallel lines are and
List all of the parallel lines in the diagram above.
|
a
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$s$ and $t$, $r$ and $v$ |
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b
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$r$ and $s$ |
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c
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$r$ and $s$, $t$ and $v$ |
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d
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$t$ and $v$ |
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e
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$s$ and $t$ |
Given the diagram above, which of the following statements is true?
|
a
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$k\parallel A$ |
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b
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$l\parallel A$ |
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c
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$k \perp l$ |
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d
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$k\perp A$ |
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e
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$k \parallel l$ |
Two lines are perpendicular if they intersect and form a angle.
For example, the lines and below are perpendicular.
When two lines are perpendicular, we can express this with the symbol as follows:
In words, we say, "the line is perpendicular to the line ."
List all of the perpendicular lines in the diagram below.
Two lines are perpendicular if they intersect and form a angle.
In the given diagram, the only perpendicular lines are and
Which of the following diagrams shows a pair of perpendicular lines?
|
a
|
 |
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b
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 |
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c
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 |
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d
|
 |
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e
|
 |
List all of the perpendicular lines in the diagram above.
|
a
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$s$ and $t$ |
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b
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$s$ and $t$, $r$ and $v$ |
|
c
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$r$ and $s$, $t$ and $v$ |
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d
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$t$ and $v$ |
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e
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$r$ and $s$ |
From the diagram above, which of the following statements is true?
|
a
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$m \perp n$ and $q \perp n$ |
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b
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$r \perp s$ and $q \perp m$ |
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c
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$q \perp r$ and $q \perp s$ |
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d
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$m \perp n$ and $r \perp s$ |
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e
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$q \perp m$ and $r \perp n$ |
In the figure above, find the parallel sides.
Two lines are parallel if they never intersect.
First, notice that the lines and are parallel.
Therefore, we conclude that the sides and are parallel. We can write this as follows:
In the figure above, find the perpendicular sides.
|
a
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$\overline{QP} \perp \overline{PR}$ |
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b
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$\overline{PQ} \perp \overline{QT}$ |
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c
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$\overline{PQ} \perp \overline{RT}$ |
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d
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$\overline{QT} \perp \overline{TR}$ |
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e
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$\overline{PR} \perp \overline{RT}$ |
In the figure above, find the parallel sides.
|
a
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$\overline{PQ} \parallel \overline{RT}$ only |
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b
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$\overline{QT} \parallel \overline{PR}$ and $\overline{PQ} \parallel \overline{PT}$ |
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c
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$\overline{QT} \parallel \overline{PR}$ and $\overline{PQ} \parallel \overline{RT}$ |
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d
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$\overline{QT} \parallel \overline{PR}$ only |
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e
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$\overline{PT} \parallel \overline{PR}$ and $\overline{PQ} \parallel \overline{RT}$ |
