Question

In the figure, / is mapped onto / by a 180° rotation. Angle B corresponds to which angle in /? A. X )B. Y) C. Z) D. C)

Answer 1

Which of the following best represents a rotation

B.

Answer 2

The correct option is B.

Explanation:

From the given diagram it is clear that the measure of angle B is 90 degrees because it is a right angled triangle.

The coordinates of vertex B are (-5,2).

If a point P(x,y) is rotate 180 degree about the origin, then

`(x,y)\rightarrow (-x,-y)`

The coordinates of image of B are

`B(-5,2)\rightarrow B'(-(-5),-(2))=B'(5,-2)`

The coordinates of image of B are (5,-2). These are the coordinates of vertex Y and the measure of angle Y is 90 degree.

The angle Y corresponds to angle B. Therefore the correct option is B.