Answer:
D. <B = 141°
Step-by-step explanation:
The sum of interior angles of a polygon is
(n-2)*180, where n is the number of sides!
Sum of angles for our polygon that has 7 sides must be:
(7-2) *180 = 5*180 = 900
Sum of angles that are in the picture are:
120+129+130+142+90+148+ <B = 759 + <B
<B = 900 -759 = 141°
Check our work:
120°+129°+130°+142°+90°+148°+ 141° = 900°✅
