If two lines l and m are parallel, then a reflection along the line l followed by a reflection along the line m is the same as a
a. translation.
b. reflection.
c. rotation.
d. composition of rotations.

A reflection along parallel line l and m is the same as a translation

Transformation is the movement of a point from its initial location to a new location. Types of transformation are rotation, reflection, translation and dilation.

A composition of reflection over two parallel lines is the same as a translation, hence:

Find out more on translation at: link

47 - 90 = 43

43 - 180 = x

x = 137