Consider [tex]\Delta AOB\cong \Delta BDC[/tex].
Given:
[tex]\Delta AOB\cong \Delta BDC, AO=5\ m,BD=10\ m, AB=5\ m.[/tex]
To find:
The length of BC.
Solution:
We have,
[tex]\Delta AOB\cong \Delta BDC[/tex]
We know that the corresponding parts of congruent triangles are congruent (CPCTC).
[tex]AB=BC[/tex] (CPCTC)
[tex]5\ m=BC[/tex]
The length of BC is 5 m. Therefore, the correct option is A.