Adinner plate fits snugly in a square box with perimeter 48 inches. what is the circumference of the plate

 The circumference of the circle is:  "37. 7 in." ;  or,  write as:
                                                                           " 12  in. " .
______________________________________________________
Explanation:
______________________________________________________
A square has all 4 (four) sides of equal length.

If the perimeter of the square = 48 inches; 

the side length of each side of the square  =  "48 in. ÷ 4 = 12 in." ; 

   →  "12 in. = the diameter, "d",  of the circle within the square" .

The formula for the Circumference, "C" , of a circle, is:

    "C =  * d " ;

         C =  * d ; 

                      d = 12 in.

C = " 12   in. " ; 

or;  calculate the Circumference, "C", of the circle; using:  "3.14" as an approximation for   ; 

C =   * d ; 

    =  (3.14) * (12 in.)  ;

    =  37.68 in. ; round to:  "37. 7 in."  .
_____________________________________________________
 The circumference of the circle is:  "37. 7 in." ;  or,  write as:
                                                                           " 12  in. " .
_____________________________________________________

Logical equivalent of the give question is its contrapositive