To find area $ A $ use formula:
$$ A = a \cdot h $$After substituting $a = 5.2\, \text{cm}$ and $h = 4.5\, \text{cm}$ we have:
$$ A = 5.2\, \text{cm} \cdot 4.5\, \text{cm} $$$$ A = 5.2\, \text{cm} \cdot 4.5\, \text{cm} $$$$ A = 23.4\, \text{cm}^2 $$