geometry question.

In $\triangle ABC$ ,$\angle B$ is the right angle.
$AC=16$ cm, and $D$ is the midpoint of $AC$.
find the length of $BD$.

$\large \color{black}{\normalsize \text{options}\hspace{.33em}\~\
a.)10\quad cm\hspace{.33em}\~\
b.)\sqrt{15}\quad cm\hspace{.33em}\~\
c.)8\quad cm\hspace{.33em}\~\
d.)7.5\quad cm\hspace{.33em}\~\
}$

Question

geometry question.

In $\triangle ABC$ ,$\angle B$ is the right angle.
$AC=16$ cm, and $D$ is the midpoint of $AC$.
find the length of $BD$.

$\large \color{black}{\normalsize \text{options}\hspace{.33em}\~\
a.)10\quad cm\hspace{.33em}\~\
b.)\sqrt{15}\quad cm\hspace{.33em}\~\
c.)8\quad cm\hspace{.33em}\~\
d.)7.5\quad cm\hspace{.33em}\~\
}$

anonymous · Answer

ok

mathmath333 · Answer

|dw:1427491456182:dw|

anonymous · Answer

what about it

nnesha · Answer

|dw:1427492460840:dw|
:D :D

nnesha · Answer

45-45-90 triangles? :D :P

mathmath333 · Answer

how is $BD$ perpendicular to $AC$

nnesha · Answer

well bec 
D is midpoint of AC so that's why   16/2

anonymous · Answer

just draw it you don't know the other sides the triangle can take many forms but 
strangely the  BD is always 4

nnesha · Answer

|dw:1427493413670:dw| hmm 
i just noticed <B is right angle

xapproachesinfinity · Answer

Nnesha that is not a right angle
the only thing the info are saying is that d is the midpoint

xapproachesinfinity · Answer

i mean not orthogonal :p

nnesha · Answer

which one ??
B or the other two :P

xapproachesinfinity · Answer

the segment bd is not orthogonal to ac

xapproachesinfinity · Answer

@mathmath333  would bd be angles bisector?

mathmath333 · Answer

No the information given does'nt  conclude that BD is the angle bisector

xapproachesinfinity · Answer

okay! i will try and see if i can find anything interesting

xapproachesinfinity · Answer

tried sin law not good lol