To find the breadth of the rectangle with a given perimeter and length, we can use the formula for the perimeter of a rectangle and solve for the breadth.
To find the breadth of the rectangle, we need to use the formula for the perimeter of a rectangle.
The formula to find the perimeter of a rectangle is: P = 2(l + b), where P is the perimeter, l is the length, and b is the breadth.
Given that the length of the rectangle is 30 cm and the perimeter is 84 cm, we can substitute the values into the formula and solve for the breadth.
P = 2(l + b)
84 = 2(30 + b)
Dividing both sides by 2, we get:
42 = 30 + b
Subtracting 30 from both sides, we have:
b = 42 - 30
b = 12
Therefore, the breadth of the rectangle is 12 cm.
Learn more about perimeter of a rectangle