Which statement is true for any polygon that is rotated 90° ?

Question

Which statement is true for any polygon that is rotated 90°?

A. Each line in the pre-image is parallel to its corresponding line in the image.

B. Each angle in the pre-image is larger than its corresponding angle in the image.

C. Each line in the pre-image is perpendicular to its corresponding line in the image.

D. Each angle in the pre-image is smaller than its corresponding angle in the image.

Answer 1

Hi Kristine,

So if you think about rotation of an object in general, you are simply turning it. Imagine if you were to look at the rotation of the earth or if you were to rotate around in a chair, it is simply turning around, which would mean that the size and shape of the object, or polygon in this case, is being preserved.

If you are preserving the size and shape of something, then you are not going to be making sides or angles smaller or larger, so it would not be B or D as a result.

Now, if we take a look at what rotating each side of a polygon 90 degrees will do, it will make each of the lines in the image perpendicular (definition of perpendicular is that it will form a right angle, or 90 degree angle at the intersection) to each of the lines in the pre-image of the polygon, therefore the answer is C.

Hope this helps!

Thanks.