Answer:
[tex]10 \times 5 = 50 \\ because \: a there \: are \: three \: of \: them \: we \: need \: to \: = \\ 50 \times 3 = 150 \\ for \: triangles = \\ 4 \times 5 \div 2 = 20 \div 2 = 10 \\ as \: far \: as \: we \: have \: two \: triangles = \\ 10 \times 2 = 20 \\ 20 + 150 = 170 \\ the \: surface = 170[/tex]
