To find area $ A $ use formula:
$$ A = a \cdot b $$After substituting $a = \dfrac{ 31 }{ 3 }\, \text{cm}$ and $b = \dfrac{ 41 }{ 4 }\, \text{cm}$ we have:
$$ A = \frac{ 31 }{ 3 }\, \text{cm} \cdot \frac{ 41 }{ 4 }\, \text{cm} $$$$ A = \frac{ 31 }{ 3 }\, \text{cm} \cdot \frac{ 41 }{ 4 }\, \text{cm} $$$$ A = \frac{ 1271 }{ 12 }\, \text{cm}^2 $$