To find area $ A $ use formula:
$$ A = a \cdot h $$After substituting $a = 3.4\, \text{cm}$ and $h = 5.6\, \text{cm}$ we have:
$$ A = 3.4\, \text{cm} \cdot 5.6\, \text{cm} $$$$ A = 3.4\, \text{cm} \cdot 5.6\, \text{cm} $$$$ A = 19.04\, \text{cm}^2 $$