How will the area of a rectangle change if one of its sides is reduced by 3 times?

Answer: will decrease by 3 times.
Solution: Suppose that the sides of the rectangle are equal to a and b, then the area of this rectangle is: S = a * b. If we reduce one of the sides (for example a), that is, a1 = a / 3, b1 = b (b1 does not change) (a1 and b1 are the sides of the new rectangle), then the area of this new rectangle is: S1 = a1 * b1 = a / 3 * b = (a * b) / 3 = S / 3. Consequently, the area of the new rectangle is 3 times less.