To find area $ A $ use formula:
$$ A = a \cdot h $$After substituting $a = 25.812\, \text{cm}$ and $h = 13.58\, \text{cm}$ we have:
$$ A = 25.812\, \text{cm} \cdot 13.58\, \text{cm} $$$$ A = 25.812\, \text{cm} \cdot 13.58\, \text{cm} $$$$ A = 350.527\, \text{cm}^2 $$