Answer:
1352 cm
Explanation:
Length (l) = 13 cm
Width (w) = 52 cm
Perimeter of the rectangle = 2(l + w) units
P = 2(13 + 8)
P = 2 (21)
P = 42
Thus, the perimeter of the rectangle is 42 cm.
Example 2: If a rectangle's length is 2x + 1 and its width is 2x – 1. If its area is 15 cm2, what are the rectangle's dimensions and what is its perimeter?
Solution:
We know that the dimensions of the rectangle in terms of x:
l = 2x + 1
w = 2x – 1
Since the area of a rectangle is given by:
A = l * w
We can substitute the expressions for length and width into the equation for area in order to determine the value of x.
A = l * w
15 = (2x + 1) (2x -1)
15 = 4x2 – 1
16 = 4x2
x = ±2
Note that the value of x must be positive and therefore in our case, the value of x is 2. And now we have:
l = 11 cm
w = 52 cm
Therefore, the dimensions are 5cm and 3cm.
Now, substituting these values in the formula for perimeter, we will get
P = 2l + 2w
P = 2(5)+2(3)
P = 10+6
P = 16 cm