Olivia wants to trim the top of a lampshade with braid. The shape that she wants to trim is a rectangle. The length of the triangle is 4 cm longer than the width. If the perimeter of the rectangle is 84 cm, what is the width and the length?
Let's assume the width of the rectangle is x cm.
According to the problem, the length will be x+4 cm.
The perimeter of a rectangle is given by the formula:
Perimeter = 2 * (width + length)
Plugging in the given information, we have:
84 = 2 * (x + x + 4)
84 = 2 * (2x + 4)
Dividing both sides by 2:
42 = 2x + 4
Subtracting 4 from both sides:
38 = 2x
Dividing both sides by 2:
x = 19
Thus, the width of the rectangle is 19 cm and the length is 19 + 4 = 23 cm.