He coordinates of point a on a grid are (−3, −2). point a is reflected across the y-axis to obtain point b. the coordinates of point b are −2).

It would be (3,-2) because you have to negate the x value when you reflect over the y-axis

The coordinates of point B are (3, -2).

Explanation:
When you reflect a point across the y axis, you keep the y coordinate the same and you find the opposite of the x coordinate. When you reflect a point across the x axis, you keep the x coordinate the same and you find the opposite of the y coordinate. In this case, since we are reflecting across the y axis, we keep the y coordinate the same (-2). Then we find the opposite of the x coordinate (the opposite of -3 is 3).

Are you trying to figure out the volume?