In the figure above, if PQRS is

Since opposite angles in a parallelogram are equal:

140 + x = 180
x = 40

Since line PQ and line SR are two parallel lines crossing through different points of the same straight line, they conform the same distribution of angles, so:

140 = 2y
y = 70

Hence:

y - x
70 - 40 = 30

Jan 25, 2015 • Comment

Mike McGarry, Magoosh Tutor

Dec 27, 2013 • Comment