[tex]L = 4 \: cm[/tex]
[tex]l = 3 \: cm[/tex]
[tex]h = 6 \: cm[/tex]
[tex]At = Al + 2Ab[/tex]
[tex]Al = 2(Lh + lh)[/tex]
[tex]Al = 2(4 \times 6 + 3 \times 6)[/tex]
[tex]Al = 2(24 + 18)[/tex]
[tex]Al = 2 \times 42[/tex]
[tex]Al = 84 \: {cm}^{2} [/tex]
[tex]Ab = L \times l[/tex]
[tex]Ab = 4 \times 3[/tex]
[tex]Ab = 12 \: {cm}^{2} [/tex]
[tex]At = Al + 2Ab[/tex]
[tex]At = 84 + 2 \times 12[/tex]
[tex]At = 84 + 24[/tex]
[tex]At = 108 \: {cm}^{2} [/tex]
