Respuesta :

Step-by-step explanation:

step 1. AD is parallel to BC

step 2. <y = 90° (definition of right trapezoid)

step 3. x + y + 90 + 140 = 360 (a quadrilateral has 360° of internal angles)

step 4. x + 90 + 90 + 140 = 360

step 5. x = 40°.