# Computer Graphics Questions & Answers – 2D Rotation

This section of our 1000+ Computer Graphics multiple choice questions focuses on 2D Rotation.

1. A two dimensional rotation is applied to an object by
a) Repositioning it along with straight line path
b) Repositioning it along with circular path
c) Only b
d) Any of the mentioned

Explanation: A two dimensional rotation is applied to an object by repositioning it along with circular path.

2. To generate a rotation , we must specify
a) Rotation angle ϴ
b) Distances dx and dy
c) Rotation distance
d) All of the mentioned

Explanation: Generate a rotation, we must specify rotation angle ϴ of the rotation point or pivot point which the object is to be rotated.

3. Positive values for the rotation angle ϴ defines
a) Counterclockwise rotations about the end points
b) Counterclockwise translation about the pivot point
c) Counterclockwise rotations about the pivot point
d) Negative direction

Explanation: A positive value for the rotation angle ϴ defines counterclockwise rotations about the pivot point.

4. The rotation axis that is perpendicular to the xy plane and passes through the pivot point is known as
a) Rotation
b) Translation
c) Scaling
d) Shearing

Explanation: The rotation transformation is also described as a rotation about a rotation axis that is perpendicular to the xy plane and passes through the pivot point.

5. The original coordinates of the point in polor coordinates are
a) X’=r cos (Ф +ϴ) and Y’=r cos (Ф +ϴ)
b) X’=r cos (Ф +ϴ) and Y’=r sin (Ф +ϴ)
c) X’=r cos (Ф -ϴ) and Y’=r cos (Ф -ϴ)
d) X’=r cos (Ф +ϴ) and Y’=r sin (Ф -ϴ)

Explanation: The original coordinates of the point in polor coordinates are X’=r cos (Ф +ϴ) and Y’=r sin (Ф +ϴ).

6. The two-dimensional rotation equation in the matrix form is
a) P’=P+T
b) P’=R*P
c) P’=P*P
d) P’=R+P

Explanation: The 2D translation equation is P’=R*P.

7. ________ is the rigid body transformation that moves object without deformation.
a) Translation
b) Scaling
c) Rotation
d) Shearing

Explanation: Rotation is the rigid body transformation that moves object without deformation.

8. An ellipse can also be rotated about its center coordinates by rotating
a) End points
b) Major and minor axes
c) Only a
d) None

Explanation: None.

Sanfoundry Global Education & Learning Series – Computer Graphics.

To practice all areas of Computer Graphics, here is complete set of 1000+ Multiple Choice Questions and Answers.