Find the perimeter of the rectangle. 11. 13 cm Area = 52 cm2​

1352 cm

Step-by-step 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

The dimension of the lawn = 85 × 40

Area of the lawn = 3250 square feet

Step-by-step explanation:

Let x represents the width of the rectangle,

Then According to the question,

The length of the rectangle = 2 x + 5

Also it is given that the perimeter of the rectangle = 250 feet.

But we know that the perimeter of the rectangle = 2 × ( length + width)

Thus, the perimeter of the rectangle = 2( 2x+5+x) = 2(3x+5) = 6x+10

If x = 30,  the perimeter of the rectangle = 6 × 30 + 10 = 190 < 250

Thus, x ≠ 10.

If x = 50,  the perimeter of the rectangle = 6 × 50 + 10 = 310 > 250

Thus, x ≠ 50

If x  = 40, the  the perimeter of the rectangle = 6 × 40 + 10 = 250 = 250

Thus, x = 40

Therefore, the width of the rectangle, x  = 40 feet.

And, the length of the rectangle, 2 x + 5 = 2 × 40 + 5 = 85 feet.

1) The dimension of the rectangle = 85 × 40

2)The area of the rectangle = length × width = 85 × 40  = 3250 square feet.