The perimeter of a rectangle is given by the following formula: P = 2W + 2L
To solve this formula for W, the goal is to isolate this variable to one side of the equation such that the width of the rectangle (W) can be solved when given its perimeter (P) and length (L).
P = 2W + 2L
subtract 2L from both sides of the equation
P - 2L = 2W + 2L - 2L
P - 2L = 2W
divide both sides of the equation by 2
(P - 2L)/2 = (2W)/2
(P - 2L)/2 = (2/2)W
(P - 2L)/2 = (1)W
(P - 2L)/2 = W
Thus, given that the perimeter (P) of a rectangle is defined by P = 2W + 2L ,
then its width (W) is given by <span>W = (P - 2L)/2</span>
Length x width = formula of finding the area of a rectangle
2 3/7 x 2 4/5 = 6 4/5 (6.8)
The area of the rectangle is 6 4/5 / 6.8
Answer: 
Step-by-step explanation:
Observe in the figure given in the exercise that four right triangles are formed.
In this case you can use the following Trigonometric Identity to solve this exercise:
From the figure you can identify that:
Then, you can substitute values:
The next step is to solve for DE in order to find its value. This is:
Finally, rounding the result to the nearest tenth, you get that this is:
