To find area $ A $ use formula:
$$ A = a \cdot b $$After substituting $a = \dfrac{ 759 }{ 25 }\, \text{cm}$ and $b = \sqrt{ 8 }\, \text{cm}$ we have:
$$ A = \frac{ 759 }{ 25 }\, \text{cm} \cdot \sqrt{ 8 }\, \text{cm} $$$$ A = \frac{ 759 }{ 25 }\, \text{cm} \cdot \sqrt{ 8 }\, \text{cm} $$$$ A = \frac{ 1518 \sqrt{ 2}}{ 25 }\, \text{cm}^2 $$