18. In a coordinate plane, triangle ABC has vertices of A(1, 1), B(1,5), and C(6, 1).
:
a. Triangle ABC is reflected across the x-axis, resulting in triangle A'B'C'.
What are the coordinates of Point B'?
b. Triangle A'B'C' is then dilated by a scale factor of 2 with the origin as the center of
dilation, resulting in triangle A"B"C". What is the length of line segment A"B"?