Question

How do i find the actual perimeter and area? 1cm:320m. L= 13.5 W= 3.3 Please explain it. I cannot understand it from the examples in my book

Answer 1

Okay, so you're given a ratio, which states that every 1cm on the book is actually 320m in real life. 320m is also just 32000cm (320 * 100)

So if the length is 13.5cm, that means you can multiply 13.5 by 32000 to get it's actual length in real life. This is 432000cm (or 4320m).

Same thing with the width. 3.3cm multiplied by 32000 will give you the width in real life, which is 105600cm (or 1056m).

I'm assuming the shape is a rectangle, so the perimeter would be 4320 + 4320 + 1056 + 1056 (because there are four sides, and two of them are the length, and two are width). So the perimeter is going to be 10752m.

The area (if it's a rectangle) will be L * W, which is just 4320 * 1056, which is Okay, so you're given a ratio, which states that every 1cm on the book is actually 320m in real life. 320m is also just 32000cm (320 * 100)

So if the length is 13.5cm, that means you can multiply 13.5 by 32000 to get it's actual length in real life. This is 432000cm (or 4320m).

Same thing with the width. 3.3cm multiplied by 32000 will give you the width in real life, which is 105600cm (or 1056m).

I'm assuming the shape is a rectangle, so the perimeter would be 4320 + 4320 + 1056 + 1056 (because there are four sides, and two of them are the length, and two are width). So the perimeter is going to be 10752m.

The area (if it's a rectangle) will be L * W, which is just 4320 * 1056, which is 4561920 m².

So that's the answer, 10752m for the perimeter and 4561920 m² for the area :)

Answer 2

To find the actual area or perimeter, you need to make the centimeters into meters. But, you have to use the scale. ( 1cm : 320m )
L=13.5
You need to multiply 13.5 and 320 (because that's how much more there is in the other model or the meter's shape)
13.5 * 320 = 4,320.
The actual Length in meters is 4,320.
Do the same with W.
3.3 * 320 = 1,056.

Now you have the real lengths.
Area = L * W
So you put in the real measurements.
Area = 4,320 * 1,056
Area = 4,561,920.
Perimeter is the sum of all sides, so Sum up all of the sides' measurements.
Hope this helps <3