Question

The perimeter of a rectangular poster is 14 feet and the length is 4 feet. Describe how to use the perimeter formula to find the width.

Answer 1

The width of rectangular poster is 3 feet.

Step-by-step explanation:

As per given question we have provided that :

• → Perimeter of rectangle = 14 feet
• → Length of rectangle = 4 feet

We need to find the width of rectangle.

Here's the required formula to find the width :

`{\underbrace{\sf{\small{ \: \: P = 2(L + W) \: \: }}}}`

• ➟ P = Perimeter
• ➟ L = Length
• ➟ W = Width

Calculating the width of rectangular poster by substituting the values in the formula :

`\begin{gathered} \qquad{\twoheadrightarrow{\sf{\small{ \: \: P = 2(L + W) \: \: }}}} \\ \\ \qquad{\twoheadrightarrow{\sf{\small{ \: \: 14 = 2(4+ W) \: \: }}}} \\ \\ \qquad{\twoheadrightarrow{\sf{\small{ \: \: (14)/(2) = (4+ W) \: \: }}}} \\ \\ \qquad{\twoheadrightarrow{\sf{\small{ \: \: 7= (4+ W) \: \: }}}} \\ \\ \qquad{\twoheadrightarrow{\sf{\small{ \: \: W = 7 - 4\: \: }}}} \\ \\ \qquad{\twoheadrightarrow{\sf{\underline{\underline{\small{ \: \: W = 3\: \: }}}}}} \end{gathered}`

Hence, the width of rectangular poster is 3 feet.

`\rule{200}2`

Answer 2

solve the equation with known values filled in; width is 3 ft.

Explanation:

The perimeter formula can be used to find a missing value by filling in all of the known values, and solving the resulting equation.

__

P = 2(L +W) . . . . . . perimeter formula

14 = 2(4 +W) . . . . . known values substituted

7 = 4 +W . . . . . . . divide by 2

3 = W . . . . . . . . . subtract 4

The width is found to be 3 feet using the perimeter formula.