1. is a rotation of 180° the same as a reflection over the y-axis? justify your answer in complete sentences.

Not the same.

Step-by-step explanation:

Given that there is a rotation of 180 degrees .  To check whether this is a reflection over the y axis.

Reflection over the y axis make the coordinates (x,y) as (-x,y)

i.e. this means rotation of 180 degrees about the origin anticlockwise.

Hence just rotation of 180 degrees is not the same as a reflection over y axis.

The conditions are:

i) 180 degree to be rotated anticlockwise

ii) Rotation is about the origin

Hence a rotation of 180 degrees need not always be the same as reflection over y axis.