The size of angles of a quadrilateral are x,x+10,x+20,x+30. What is the size of each angle?

We know that the sum of the interior angles in a polygon
with n sides is 180*(n-2).

The number of sides in a
quadrilateral is n = 4, therefore the sum of the interior angles is 180*(4-2) = 180*2 =
360 degrees

Therefore, we'll add the given measures of
angles:

x + x + 10 + x + 20 + x + 30 =
360

4x + 60 = 360

4x = 360 -
60

4x = 300

x = 75
degrees

x + 10 = 75 + 10 = 85
degrees

x + 20 = 75 + 20 = 95
degrees

x + 30 = 75 + 30 = 105
degrees

The interior angles of the
quadrilateral are: 75 ; 85 ; 95 ; 105
degrees.