Answer:
110 degrees
Step-by-step explanation:
Ok so in a quadrilateral, the sum of the interior angles have to add up to 360 degrees*.
This means that x + 128 + 82 + 40 = 360, so you can solve this as an equation:
x + 128 + 82 + 40 = 360
x + 250 = 360
x = 110 degrees
*The reason the interior angles of a quadrilateral add up to 360 degrees is because the formula for the sum of the interior angles in a polygon is
180 * (n - 2) where n is the number of sides, so since this polygon has 4 sides it would be:
180 * (4 - 2)
180 * 2
360 degrees
Hope that makes sense!
