Answer:
a. 72°
Step-by-step explanation:
The sum of angles in a triangle is 180°. The two base angles of an isosceles triangle (one with two congruent sides) are congruent, so we have ...
54° + 54° + x° = 180°
x° = 180° - 108°
x° = 72°
I think it is hexagon. It says which polygon at the bottom, and hexagons have six sides like the figure above.
E1,1 F5,3 G5,7 H1,6 bc when rotating 90 a,b becomes -b,a
-x on both sides to get
x=15
