Find the angle measure of x in the following figures.

(a)Sum of all interior angles of quadrilateral=360°
∴50+130+120+x=360
x=60°
(b)90+a=180
a=90°
Sum of all angles of quad=360
x+70+60+90=360
x=140°
(c)70+a=180 (Linear pair)
a=110°
60+b=180 (Linear pair)
b=120°
Sum of measures of all angles of pentagon=540°
∴120+110+x+x+30=540
2x=280
x=140°
(d)Sum of all angles of pentagon=540°
Given all angles are equal
∴5x=540
x=108°