The perimeter of the rectangle below is 28.
Calculate the value of x.
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The perimeter of the rectangle below is 28.
Calculate the value of x.
To solve this problem, we'll follow these steps:
Now, let's work through each step:
Step 1: The problem gives us that the perimeter of the rectangle is 28, one side (length) is 11, and the other side (width) is .
Step 2: We'll use the formula for the perimeter of a rectangle: . In this problem, and so:
Step 3: Divide both sides by 2 to isolate the expression inside the parentheses:
Step 4: Subtract 11 from both sides to solve for :
Therefore, the value of is .
3
Look at the rectangle below.
Side DC has a length of 1.5 cm and side AD has a length of 9.5 cm.
What is the perimeter of the rectangle?
It doesn't matter! In this problem, whether you call 11 the length or width, x will still equal 3. The perimeter formula works the same way regardless of which dimension you label as length or width.
Because a rectangle has 4 sides: 2 lengths and 2 widths. Instead of adding all four sides separately, we use as a shortcut to multiply the sum by 2.
Check your arithmetic! In geometry problems, dimensions are always positive numbers. If you get negative, you likely made a calculation error somewhere.
You could, but it's not efficient! Using the algebraic method gives you the exact answer in just a few steps, and it works for any numbers - not just simple ones.
After substituting into , you need to isolate what's in parentheses. Since it's multiplied by 2, you divide both sides by 2 to undo that operation.
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