Respuesta :

The area of the two triangular faces is
  triangle area = (10 cm)·(24 cm) = 240 cm²

The area of the rectangular faces is
  (23 cm)·(24 cm + 10 cm + 26 cm) = 1380 cm²

The total area is the sum of these
  240 cm² + 1380 cm² = 1620 cm²