Volume is length x width x height. It measures how much space it can hold inside of a shape.
No a polygon only has 3 sides and 3 angles.
From angle bisector theorem, we know that:

Moreover:

so:

and
Answer:
x=75
Step-by-step explanation:
A( I mean angle)+B+C+D=360°
A=C
B=D
2A+2D=360°
A+D=180°
30°+x+x=180°
2x=150°
x=75