Whenever two parallel lines are cut by a transversal, any pair of adjacent angles (angles that have a common side) form a linear pair. In other words, they are supplementary, and the sum of their measures is
In total, there are pairs of adjacent angles. These are shown below.
Solve for in the figure above given that
First, notice that and are corresponding angles. Therefore, their measures are equal.
Also, the angles and are supplementary. So, we have:
Solve for $x$ in the figure above given that $\overset{\longleftrightarrow}{AB} \parallel \overset{\longleftrightarrow}{CD}.$
a
|
$40^\circ$ |
b
|
$27^\circ$ |
c
|
$35^\circ$ |
d
|
$30^\circ$ |
e
|
$33^\circ$ |
Solve for $x$ in the figure above given that $\overset{\longleftrightarrow}{AB} \parallel \overset{\longleftrightarrow}{CD}.$
a
|
$3^\circ$ |
b
|
$9^\circ$ |
c
|
$14^\circ$ |
d
|
$7^\circ$ |
e
|
$11^\circ$ |
Consecutive interior angles are the pairs of angles that are consecutive (on the same side of the transversal) and interior to (inside of) the parallel lines. These pairs of angles are always supplementary.
Consecutive exterior angles are angles that are consecutive (on the same side of the transversal) and exterior to (outside of) the parallel lines. These pairs of angles are always supplementary.
Solve for in the figure below given that
We notice that and are consecutive interior angles. Therefore, they are supplementary, and the sum of their measures is
So, we have:
Solve for $y$ in the figure above given that $\overset{\longleftrightarrow}{AB} \parallel \overset{\longleftrightarrow}{CD}.$
a
|
$90^\circ$ |
b
|
$80^\circ$ |
c
|
$65^\circ$ |
d
|
$60^\circ$ |
e
|
$70^\circ$ |
Solve for $x$ in the figure above given that $\overset{\longleftrightarrow}{AB} \parallel \overset{\longleftrightarrow}{CD}.$
a
|
$39^\circ$ |
b
|
$35^\circ$ |
c
|
$37^\circ$ |
d
|
$36^\circ$ |
e
|
$33^\circ$ |
Solve for in the figure below given that
We notice that and are consecutive exterior angles. Therefore, they are supplementary, and the sum of their measures is Therefore, we have
Solve for $x$ in the figure above given that $\overset{\longleftrightarrow}{AB} \parallel \overset{\longleftrightarrow}{CD}.$
a
|
$140^\circ$ |
b
|
$135^\circ$ |
c
|
$150^\circ$ |
d
|
$130^\circ$ |
e
|
$145^\circ$ |
Solve for $x$ in the figure above given that $\overset{\longleftrightarrow}{AB} \parallel \overset{\longleftrightarrow}{CD}.$
a
|
$50^\circ$ |
b
|
$70^\circ$ |
c
|
$40^\circ$ |
d
|
$60^\circ$ |
e
|
$30^\circ$ |
Solve for given that and
Consider and in the diagram below.
First, notice that and are consecutive interior angles formed by the same transversal. Therefore,
Now, notice that and are alternate interior angles formed by another transversal. Therefore,
Finally, angles and form a straight angle. So, we obtain:
Given that $r$, $s$ and $t$ in the above diagram are parallel, find $m\angle 1.$
a
|
$95^\circ$ |
b
|
$89^\circ$ |
c
|
$91^\circ$ |
d
|
$81^\circ$ |
e
|
$99^\circ$ |
Solve for $x$ given that $s \parallel t,$ and \begin{align*} m\angle{1} = 4x-10^{\circ}, \qquad m\angle{2} = x+19^{\circ}, \qquad m\angle{3} = 2x + 9^{\circ}. \end{align*}
a
|
$4^{\circ}$ |
b
|
$11^{\circ}$ |
c
|
$5^{\circ}$ |
d
|
$7^{\circ}$ |
e
|
$8^{\circ}$ |