Question

Can anyone please answer the question.

Answer 1

Please have close at the picture that I have attached,

If we can review our knowledge on mirror we can say that,

Incident angle = reflected angle

From this picture we can write,

angle ABH = angle HBD

we will take this angle as i

Then since FBH is 90 degrees we can write,

angle DBF = 90-i

Since BFD is a rectangular triangle,

angle FDB = i

Then for the second mirror,

angle BDL = 90-i

Since angle BDL = angle LDC (incident and reflected angles)

angle LDC = 90-i

Then,

angle BDC = (90-i) + (90-i)

                  = (180-2i)

And also angle ABD = 2i

Then by taking,

angle BDC + angle ABD = 2i + 180-2i

                                        = 180 degrees

Because the addition of two interior angles BDC and ABD is 180 degrees we can conclude that AB and DC are parallel lines.