Answer: 390 m².
Step-by-step explanation:
[tex]Surface \ area = 11*13+11*12+11*5+2*\frac{12*5}{2}=11*(13+12)+11*5+12*5=\\ =11*25+5*(11+12)=275+5*23=275+115=390\ (m^2).[/tex]
