the lenghth of a rectangle is fixed at 20cm what widths will make the perimeter greater than 72cm?
72 - 40 = 32
32 / 2 = ?
To find the range of widths that will make the perimeter of a rectangle greater than 72 cm, we need to consider the perimeter formula for a rectangle: P = 2*(length + width).
Given that the length is fixed at 20 cm, we can substitute this value into the formula: 72 > 2*(20 + width).
Now, let's solve for the width:
72 > 40 + 2*width
Subtracting 40 from both sides of the inequality:
32 > 2*width
Dividing both sides by 2:
16 > width
Therefore, any widths greater than 16 cm will make the perimeter of the rectangle greater than 72 cm.