question_answer

In \[\Delta \text{ABC},\angle \text{A}=\text{9}0{}^\circ \]and \[AD\pm BC.\]If AB= 5 cm, BC = a cm and AC = b cm, find the length of BD in cm.

A)  \[\left( \frac{{{b}^{2}}-{{a}^{2}}+25}{a} \right)\]              

B)  \[\left( \frac{{{a}^{2}}-{{b}^{2}}+25}{2a} \right)\]

C)  \[\left( \frac{{{a}^{2}}-{{b}^{2}}+25}{2b} \right)\]            

D)  \[\left( \frac{{{a}^{2}}-{{b}^{2}}+25}{2a} \right)\]