What is the angle of the rotation about C the maps the solid figure to the dashed figured?

tinypic(.)com/r/2utnvoo/9

Choices:
90Â°

Question

What is the angle of the rotation about C the maps the solid figure to the dashed figured? 

tinypic(.)com/r/2utnvoo/9 

Choices: 
90Â° <<<< my answer 
180Â° 
270Â° 
360Â°

mathmate · Answer

@Sageee
Unlike certain sites, at OpenStudy, you don't have to hide a link.  (.)
The question is very tricky because it does not mention the direction of rotation (clockwise  or counter-clockwise (CCW)).
I do not know what your teacher/software assumes, but in trigonometry, the default is counter-clockwise.
Can you give me the complete answer, i.e. angle and direction, but I will let you choose the choices according to your teacher/software.

likeabossssssss · Answer

$\Huge\color{#EB00FF}{\text{WELCOME}}$ $\Huge\color{blue}{\text{TO}}$ $\Huge\color{green}{\text{OPEN}}$$\Huge\color{purple }{\text{ STUDY!!!!!!!!!!!}}$ $\Huge\heartsuit$