ANSWER
The surface area of the brick is;
[tex]650 \: {cm}^{2} [/tex]
EXPLANATION
The dimensions of the rectangular brick are
[tex]l = 5cm[/tex]
[tex]w = 9cm[/tex]
[tex]h = 20cm[/tex]
The total surface area of a rectangular brick is given by,
[tex]T.S.A = 2(lw + lh + hw)[/tex]
We substitute the values into the formula to obtain,
[tex]T.S.A = 2(5 \times 9 + 5 \times 20 + 9 \times 20)[/tex]
[tex]T.S.A = 2(45+ 100+ 180)[/tex]
[tex]T.S.A = 2(325)[/tex]
[tex]T.S.A =650 \: {cm}^{2} [/tex]
