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Perimeters

Formulas and instructions for finding the perimeters of circles (circumferences), kites, parallelograms, rectangles, rhombi, squares, trapezoids and oddly shaped geometric objects
Just scroll down or click on what you want and I'll scroll down for you!
 

circumference of a circle perimeter of a kite perimeter of a parallelogram
perimeter of a rectangle perimeter of a rhombus perimeter of a square
perimeter of a trapezoid perimeter of an oddly
shaped geometric figure
 

 

The circumference of a circle (the perimeter of a circle):

circle graphic

The circumference of a circle is the perimeter -- the distance around the outer edge.

Circumference = circle graphic
where r = the radius of the circle
and pi = 3.141592...

 

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The perimeter of a kite:

To find the perimeter of a kite, just add up all the lengths of the sides:

perimeter of a kite = a+a+b+b =  2a+2b

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The perimeter of a parallelogram:
parallelogram
To find the perimeter of a parallelogram, just add up all the lengths of the sides:

    Perimeter 
    = a + b + a + b
    = 2a + 2b

 

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The perimeter of a rectangle:

rectangle

To find the perimeter of a rectangle, just add up all the lengths of the sides:

Perimeter = L + w + L + w
        = 2L + 2w

 

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The perimeter of a rhombus:

To find the perimeter of a rhombus, just add up all the lengths of the sides:

Perimeter of a rhombus = x+x+x+x = 4x

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The perimeter of a square:

To find the perimeter of a square, just add up all the lengths of the sides:

Perimeter = x+x+x+x = 4x

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The perimeter of a trapezoid:
trapezoid To find the perimeter of a trapezoid, just add up all the lengths of the sides:

Perimeter = a + b + c + B

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How to find the perimeter of strangely shaped objects:

Let's find the perimeter of this thing...  We, basically, need to add up all the outside edges.  And we'll just have to do that piece by piece!

geometric shape

Here are all the missing pieces:

geometric shape

Now, add them all up!

5 + 8 + 6.28 + 6 + 2 + 2 + 2 + 3 = 34.28