Answer:
See Explanation
Step-by-step explanation:
The question has unclear information.
So, I'll answer from scratch
Given
ABC = Right angled triangle
DB bisects ABC
Required
Prove that CBD = 45
From the question, we have that:
ABC is right angled at B
So, when DB bisects ABC, it means that DB divides ABC into two equal angles.
i.e.

and

Substitute CBD for ABD in 


Divide both sides by 2



Hence, it is proved that 
<em>Follow the above explanation and use it to answer your question properly</em>