Okay, here we have this:
Considering the provided figure, we are going to calculate the requested surface area, so we obtain the following:
Then we will substitute in the following formula:
Surface area=Area of bottom rectangle+Area of front rectangle+Area of back rectangle+2(Area of side triangle)
Surface area=(12cm*15cm)+(20cm*15cm)+(15cm*16cm)+2((12cm*16cm)/2)
Surface area=(12cm*15cm)+(20cm*15cm)+(15cm*16cm)+(12cm*16cm)
Surface area=(12cm*15cm)+(20cm*15cm)+(15cm*16cm)+(12cm*16cm)
Surface area=180cm^2+300cm^2+240cm^2+192cm^2
Surface area=180cm^2+300cm^2+240cm^2+192cm^2
Surface area=912cm^2
Finally we obtain that the surface area of the tringular prism is 912cm^2.