A rectangular block is 2 cm wider than it is high and twice as long as it it wide. Let x cm be the height of the block.

Find an expression for the total surface area, A cm2, in term of x.

3 answers

Let L,W and H be the dimensions of the rectangular block.

Total surface area
A=2(LW+WH+HL)

So if
H=height=x
then
W=x+2, and
L=2W=2(x+2)
Substitute these values of H,W and L into the equation for A and simplify.
on a piece of paper draw a rectangle paddock 20 cm long and 10 cm wide
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on a piece of paper draw a rectangle paddock 20 cm long and 10 cm wide ?