Square with perpendicular lines drawn, prove that they are equal.

Question

ABCD is a square. C' is a point on BA and B' is a point on AD such that BB' and CC' are perpendicular. Show that BB' = CC'

I don't know where to start. Use similarities?

Answer 1

$\alpha = \alpha ‘$ because they are both complement to $\beta$.

Then, by ASA, $\triangle B’AB \cong \triangle C’BC$.

Result follows.

Answer 2

I am attaching the solution please go through it. This can be done by using co ordinate geometry that I have shown in my solution.