I really need help on this geometry question, please, and thank you.

Answer:
250
Step-by-step explanation:
you have to use the fact that the big triangle and the small triangle are similar and write the proportions
[tex]\frac{125}{10} =\frac{AB}{10}[/tex] we took half of the side because of ΔABD and ΔBD..
AB= (125*10)/10=125
is AB =125 then AC is duble AC= 2*125=250