m of AA1 = $\frac{7--1}{2-6} \ = -2$
m of mirror line = $\frac{1}{2}$
Mid point of AA1 = $\frac{2 + 6}{2}, \frac{7 \pm 1}{2}$
x = 4, 3
$\frac{y - 3}{x - 4} \ = \frac{1}{2}$
y = $\frac{1}{2} + 1$
raphael answered the question on January 16, 2017 at 12:46