An object is rotated 180 deg about a center, C, if and only if the two lines intersecting at C that are used for the rotation form a ___ angle.

180°

Step-by-step explanation:

The given information are;

The of the object = 180°

Therefore, a line drawn though the a point on the preimage passing through the center of rotation

A second line is drawn from the center of rotation, towards the direction of the expected location of the image of the chosen point on the preimage which should in this case be 180° and the distance from the location of the point on the image to the given center of rotation should be the same as the distance of the point of the preimage from the given center of rotation.

step-by-step explanation: