Answer:
the first one
Step-by-step explanation:
the two planes intersect at line YZ, where they meet
tip: planes intersects at a line, just like how lines intersect at a point
hope this helps :)
This would be a reflection.
Angles in a parallelogram have to equal 360.
Let x represent the measurement of the unknown angle.
2(55) + 2x = 360
110 + 2x = 360
2x = 250
x = 125
125 degrees