If a circular plate has a diameter of 9 inches. what is the area of the plate

 The area of the circular plate is:  " 63.59 in² " .
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Note:
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diameter, "d" = 9 in. (given). 

radius, "r" = "d/ 2 " = "(9 inches) / 2 " = 4.5 in. 
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Area of a circle, "A" :

A =  * r²  ; 

in which:   "A = Area of circle ("plate"); in units of "square inches"; or "in² " ;
 
                  " = 3.14 " {approximation we shall use} ;  

                  "r = radius = 4.5 in." ;
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Plug in our known values to solve for the area, "A" :

A = (3.14) * (4.5 in)² ;

A = (3.14) * (4.5)² * (in²) ; 
 
A = (3.14) * (4.5) * (4.5) * (in²) ; 

A = 63.585 in² ; round to:  " 63.59 in² " .
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Best answer that i found on yahoo ok   set :   x= length of 2nd piece in cm  x- 3= length of 1st piece in cm  x-4= length of 3rd piece in cm  then since you know they all came from the 20 cm ribbon you add them together and set them equal to 20x+ x-3 +x-4 = 20  3x - 7= 20  3x= 27  x= 9  the shortest piece is the third piece which is x- 4  x-4  9-4 = 5  the length of the smallest piece is 5 cm.  the other lengths are  9 cm  6 cm