### Video Transcript

Work out the value of đť‘Ą in the
figure.

đť‘Ą is an angle thatâ€™s measured in
degrees, and thereâ€™s another angle that measures 131 degrees. We have a set of parallel lines
that are cut by a transversal. This means the angle thatâ€™s 131
degrees is going to be equal to another angle that is supplementary to đť‘Ą.

We know the angles measuring 131
degrees are equal because they are alternate exterior angles; theyâ€™re on alternate
sides of the transversal and on the exterior of the parallel lines.

So these two angles should add to
180 degrees because they form a linear pair; they create a line, which is 180
degrees; they are supplementary. Therefore, we can say 131 plus đť‘Ą
equals 180 because these two angles added together will combine to equal 180
degrees.

So to solve for đť‘Ą, we need to
subtract both sides by 131. And we get that đť‘Ą is equal to
49. Therefore, the value of đť‘Ą in our
figure is 49 degrees.