Answer: x = 75
Step-by-step explanation: The first thing to note is that what we have here is a quadrilateral. In other words, all the internal angles sum up to 360°. Also take note that the figure is a parallelogram, which means two sides are parallel to each other. Line AD is parallel to BC, and line DC is parallel to AB. That makes angle D equal to angle B (alternate angles), and angle A equals Angle C.
If the sum of the interior angles of a quadrilateral equals 360, then
x + (x + 30) + x + (x + 30) = 360
x + x + 30 + x + x + 30 = 360
Collecting like terms, we have
x + x + x + x + 30 + 30 = 360
4x + 60 = 360
Subtract 60 from both sides of the equation
4x = 300
Divide both sides of the equation by 4
x = 75.
