Answer:
20°
Step-by-step explanation:
40°, 70° and 90° are the measures of the three angles of the quadrilateral.
Measure of fourth angle of the Quadrilateral
= 360° - (40° + 70° + 90°)
= 360° - 200°
= 160°
Measure of angle 1 will be equal to the measure of the linear pair angle of 160° as they are corresponding angles.
Thus,
Alternate method: