Question

Find the measure of the angle of rotation about D that maps the solid-line figure onto the dotted-line figure.
http://www.intervisualtechnology.us/data/1/17032/u9l3q10.JPG
a) 90
b) 120
c) 150
d) 180

Answer 1

Pick one point on the solid line figure.
For example, pick the point that looks like the tip of the right arrowhead.
Now draw a segment from the center of the figure, point D, to that point.

Locate where the corresponding point is in the rotated figure.
Draw a segment from the center of the figure to the rotated points.

Now use point D as the vertex of an angle, and the two segments you drew as sides of the angle, and measure the angle.

Answer 2

i think it is b

Answer 3

is that correct

Answer 4

Yes.