First, you have to find out the missing angle of the quadrilateral. We know that there are two right angles, one angle measuring 110° degrees, and that all the angles must add up to 360°. We can use the equation 90+90+110+x=360 290+x=360 x=70 Now that we found the missing angle, we have the find the value of x. We know that since it is a straight line, the two angels must add up to 180° We can use the equation 70+x=180 x=110 Therefore the value of x is 110°