Respuesta :

The base is a square, therefore all the sides of the base  are the same. This also means all the triangles have the  same area.

10*10 = 100 cm^2 for the base

0.5*10*12 = 60 cm^2 for each triangle

100 + 4(60) = 340 cm^2
10*10

0.5*10*12 

340cm^2

Hope this helps