Question

Длина прямоугольника увеличена на 60%,а ширина уменьшена на 60%.Как изменится площадь прямоугольника? На сколко процентов увеличится площадь прямоугольника если его длинну увеличить на 40%, а ширину на 10%? На сколко процентов уменьшится площадь прямоугольника если его длинну уменьшить на 20%, а ширину на 60%? Плиз решите!!! Даю 40 баллов!!!

Answer 1

S=a*b
a- ширина, b - длина

1) 1.6*b -увеличили длину на 60%
    0.4*a -уменьшили ширину на 60%
   S=1.6b*0.4a=0.64*ab - новая площадь уменьшилась на 36%

2) 1.4*b -увеличили длину на 40%
     1.1*a -увеличили ширину на 10%
    S=1.4b*1.1a=1.54*ab - новая площадь увеличилась на 54%

3) 0.8*b - уменьшили длину на 20%
    0.4*a - уменьшили ширину на 60%
    S=0/8b*0.4a=0.32*ab - новая площадь уменьшилась на 68%

Answer 2

Calculation of Rectangle Area

To calculate the area of a rectangle, we multiply its length by its width.

Let's consider the initial rectangle with length L and width W.

1. When the length of the rectangle is increased by 60% and the width is decreased by 60%, the new length becomes 1.6L and the new width becomes 0.4W.

The new area of the rectangle can be calculated as follows: New Area = (1.6L) * (0.4W) = 0.64 * L * W

Therefore, the area of the rectangle is reduced to 64% of its original area.

2. When the length of the rectangle is increased by 40% and the width is increased by 10%, the new length becomes 1.4L and the new width becomes 1.1W.

The new area of the rectangle can be calculated as follows: New Area = (1.4L) * (1.1W) = 1.54 * L * W

Therefore, the area of the rectangle is increased to 154% of its original area.

3. When the length of the rectangle is decreased by 20% and the width is decreased by 60%, the new length becomes 0.8L and the new width becomes 0.4W.

The new area of the rectangle can be calculated as follows: New Area = (0.8L) * (0.4W) = 0.32 * L * W

Therefore, the area of the rectangle is reduced to 32% of its original area.

Please note that these calculations assume that the length and width are independent of each other and that the changes are applied proportionally.

I hope this helps! Let me know if you have any further questions.