A square of the sides are decreasing by 20% .what is the net change of area?

1 Answer
Apr 25, 2018

The net change of area is a decrease of 36%

Explanation:

Let's say the original square has sides of length x. Therefore, it will have an area of x*x, or x^2.
Now, we know that our new square's sides are decreasing by 20%. This will result in a length 80% of the original square, because 20%+80%=100%. So, we can state the area of the new square as (80%*x)(80%*x), or more simply 0.8x*0.8x. By combining like terms, we can simplify this equation to 0.64x^2. Therefore, the net change in area is a decrease of 100%-64%, or 36% using the same form as the question.