SOLUTION: If the length of the base of a triangle is increased by 10 percent and the height is decreased by 20 percent, what is the percent decrease in the area of the triangle?

Question 366099: If the length of the base of a triangle is increased by 10 percent and the height is decreased by 20 percent, what is the percent decrease in the area of the triangle?
Answer by fractalier(6550) (Show Source): You can put this solution on YOUR website!
We can express the original area of a triangle as

If the new base is 10% greater, the new b is (1.1)b.
If the new height is 20% less, the new h is (0.8)h.
Now substituting, we get
=

Notice how the original area is only 88% of what it was...
So there was a 12% decrease in area.

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