How many percent will the area of the square increase if its side is increased by 30%.

Let’s denote the side of the square by x. Then the area of the square is x ^ 2.
If the side of the square is increased by 30%, then the side of the square becomes equal to:
x + (30/100) * x = x + (3/10) * x = x + 0.3 * x = 1.3 * x.
The area of the square with the enlarged side is (1.3 * x) ^ 2 = 1.69 * x ^ 2.
In relation to the area of the original square x ^ 2, the area of the enlarged square increased by
((1.69 * x ^ 2 – x ^ 2) / x ^ 2) * 100 = ((0.69 * x ^ 2) / x ^ 2) * 100 = 0.69 * 100 = 69 percent.

Answer: The area of the square will increase by 69 percent.