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put this solution on YOUR website!if L = length of triangle
W = width of triangle
Then the area of the triangle would be:
eq.1)

the length of a rectangle is increased by 12 and the width is decreased by 8,the area is unchanged:
eq.2)

The area is also unchanged if the original length is increased by 5 and the original width is decreased by 4:
eq.3)

Substituting LW for A in eq2:

Substituting LW for A and (8 + (2/3)L) for W in eq3:

Dimensions of the triangle:
length is 30 units
width is 28 units
area is 840 square units