jmc

The area of a rhombus can be expressed as: $\frac{d_1{d}_2}{2}$, where $d_1,d_2$ are the lengths of the diagonals. (Think of each quadrant as a triangle, and sum those areas - you'll see it comes out to this formula) Plugging in $d_1=24$ and $d_2=10$, we get $\frac{24\cdot 10}{2}=\boxed{120}$ square units.