Theorem 1: Two graphs symmetric about a straight line are conformal.

Theorem 2: If two figures are symmetrical about a straight line, then the symmetry axis is the perpendicular line connecting the corresponding points.

Theorem 3: Two figures are symmetrical about a straight line. If the axis of symmetry intersects the extension lines of two symmetrical line segments, the intersection point is on the axis of symmetry.

Let's go

Theorem 3 Inverse Theorem: If the straight line connecting the corresponding points of two graphs is vertically bisected by the same straight line, then the two graphs are symmetrical about this straight line.

I hope it helps you.