please help me fast and show all your work please thx

If the two diagonals are [tex]d[/tex] and [tex]D[/tex], the are of the rhombus is
[tex]A=\dfrac{dD}{2}[/tex]
So, in your case, the area is
[tex]A=\dfrac{15\cdot 35}{2}=262.5[/tex]
The other options are wrong because: