Answer:
x = 78 degrees
Step-by-step explanation:
Let y represent the last angle in the triangle containing 79 degrees and x degrees.
Since the top and bottom lines are parallel, then angle y and angle 23 are alternate angles. Alternate angles are equal. Therefore,
Angle y = 23 degrees
The sum of the angles in a triangle is 180 degrees. It means that
Angle x + angle y + 79 degrees = 180 degrees. Therefore
x + 23 + 79 = 180
x + 102 = 180
Subtracting 102 from the left hand side of the equation and the right hand side of the equation, it becomes
x + 102 - 102 = 180 - 102
x = 78 degrees
