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### Course: Class 7 (Old)>Unit 9

Lesson 1: Squares and rectangles

# Area & perimeter word problem: dog pen

Sal figures out the width of a dog pen. Created by Sal Khan.

## Want to join the conversation?

• How would you figure the area of a pentagon?
• yeah how would you I never thought about that.
• Lisa built a rectangular flower garden that is 4 feet wide and has a perimeter of 26 feet.
• First, you multiply the width by 2. The product is 8. Next, you subtract 8 from the perimeter which is 26, and the difference is 18. Afterwards, 18/2 = 9. This means that 9 is the length. If you want to figure out the area, just multiply 4 and 9, and the product is 36 feet squared.
• How to calculate depth?
• Depth is not something that you would calculate so much as you would just measure it. You would need a starting place - something like sea level (the surface of the sea), then you would just measure down to the bottom to find depth.
• Is there another way of doing this?
For example, what I learned was 78/2 and then take that answer and subtract by the one length that the problem gives you, because the formula that I learned was 2(L+W).

And also, which is the fastest and easiest way of doing this??
• there is definitely many ways to solve the problem. the way you mentioned is one of them.
• *What if they don't give you the length? And they just give you the area and height?*
• do the same thing but with the height in the place of the length
• im stuc

The area of a square is 144 square centimeters.
What is the length of one side of the square?
• The area of a square is the side length times itself. So we need to find what positive number times itself would give 144. This positive number is 12. (This process is called taking the square root.)

The area is given in square centimeters, so the side length is in centimeters.

So the side length is 12 centimeters.
• how do you find the area of a cricle
• The formula is pi times the radius squared.
I hope this helped a bit!
Edit: Ask me if you need help :)
• At Arcane.
Well for starters, I keep getting the formulas mixed up, word problems are not my strong suit, I know they different things, but they sound the same. I'm doing my best, but I'm not good with words, so I'll try to give you my best example.
The question up in the video, I don't even know where to begin with that one! I don't know how to get started, I can finish it. What's area and priemeter?? And how to know when to multiply and add. I already know how to do those. I'm not sure if that made any sense.(Sweat)I'm not complaining, I'm sorta desperate, although I'm just passing by. However, if anyone can like give me a tip! I'll be grateful, you just helped out a person in need. (Me Blushing Sheepish)I'm willing to learn. Please.

June 27th, 2021.
• The perimeter is the total distance around the edges of a shape. So we add the edges to find the perimeter. This means that the perimeter of a rectangle is twice the length plus twice the width.

The area is the amount of space (or number of unit squares) inside the shape. So if the figure is a rectangle, we can multiply length times width to find the area.

Have a blessed, wonderful day!