I believe the answer for 17 is C. 18 I am not sure how to do. For 19, however, the answer is B. Hope I help, and sorry I can't answer 18.
She will use 3 rows of 3 squares, for a total of 9 squares.
Since the shape she is covering is a square, all of the sides are equal. If 3 square tiles fit across the width of the top, then 3 square tiles fit across the length of it as well. This makes 3 by 3, or 9 squares.
The answer is for that problem is -3
I'm pretty sure it's no...
