Perimeter & Area are a part of the GED Math test.
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Video Transcription
Let’s start with something simple and really useful—area and perimeter. These are the kinds of questions that often show up on math tests. Once you understand the basics, they’re some of the easiest points you can earn.
What Is Perimeter?
Perimeter is the distance all the way around a shape.
Think of a garden that is 10 feet long and 5 feet wide
To find the perimeter, add all the sides: 10 + 5 + 10 + 5 = 30 feet
Or use the formula: Perimeter = 2 × (length + width) Perimeter = 2 × (10 + 5) = 2 × 15 = 30 feet
So the perimeter of the garden is 30 feet.
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What Is Area?
Area is the space inside a shape.
For a rectangle, the formula is: Area = length × width
Using the same garden: Area = 10 × 5 = 50 square feet
So the area is 50 square feet.
Finding a Missing Side Using Area
Sometimes you’re given the area and one side, and you have to find the missing side.
Example: A garden has Area = 48 square feet, Width = 6 feet, Length = ?
Use the area formula: Area = length × width, 48 = x × 6
Solve for x: x = 48 ÷ 6, x = 8
So the length is 8 feet.
Finding a Missing Side Using Perimeter
Now, let’s say you’re given the perimeter and one side, and need to find the other side.
Example: A pool has Perimeter = 34 feet, Length = 10 feet, Width = ?
Use the perimeter formula: Perimeter = 2 × (length + width), 34 = 2 × (10 + x)
Step-by-step: 34 = 20 + 2x, 14 = 2x, x = 14 ÷ 2, x = 7
So the width is 7 feet.
Final Tip
Once you know the formulas, you just plug in what you’re given and solve step by step. Whether you’re working with area or perimeter, it’s all about understanding the shape and using simple math to fill in the blanks.
Last Updated on October 20, 2025.