ABC and DBC are on the same base BC but on opposite sides of it. AD and BC intersect each other O. If AO=a cm, DO=b cm and the area of ABC= x cm2, then what is the area (in cm2) of DBC?

• A. $${ab over 2}{x}$$
• B. $${a over b}{x}$$
• C. $${b over a}{x}$$
• D. $${a+b over2}{x}$$