**In figure, ABC and ABD are two triangles on the same base AB. If line- segment CD is bisected by AB at O, show that ar(ABC) = ar (ABD).**

**Solution:**

We need to show that

It is given that OC=OD. It means that AO is the median of . Also, BO is the median of .

** (1)**

**(Median of a triangle divides it into two triangles of equal areas.)**

And, ** (2)**

**(Median of a triangle divides it into two triangles of equal areas.)**

Adding **(1)** and **(2)**, we get