Program4-Write a program to find the area of rectangle in PL/SQL

Method-1:
=================
Suppose rectangle have length and breadth .so area of rectangle is multiplication of length and width.
Input-length=20 meters and width=10 meters
Output-200 meter square
Operation- area of rectangle=length*width

Code-
SQL> set serveroutput on;
SQL> declare
  2      length  number;
  3      width  number;
  4      Begin
  5         length  :=20;
  6         width :=10;
  7     Dbms_output.put_line('Area of the Rectangle='||length*width);
  8     End;
  9  /
Area of the Rectangle=200

PL/SQL procedure successfully completed.
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Method-2:
=======================
Input-Take two variables length and width  and store the result into third variable result.
Output- Area of the rectangle
Operation- result=length*width

SQL> declare
  2      length  number;
  3      width  number;
  4     result number;
  5      Begin
  6         length  :=20;
  7         width :=10;
  8        result:=length*width;
  9     Dbms_output.put_line('Area of the Rectangle='||result);
 10     End;
 11  /
Area of the Rectangle=200

PL/SQL procedure successfully completed.

SQL>
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Method-3:
====================
Input-Ask user to enter two number  length and width  and store the result into third variable rec_area.
Output- rec_area
Operation-Area of rectangle

Code-
SQL> declare
  2      length  number;
  3      width  number;
  4      rec_area number;
  5      Begin
  6         length :=&length ;
  7         width :=&width;
  8      rec_area :=length*width;
  9
 10     Dbms_output.put_line('Area of the Rectangle='||rec_area);
 11     End;
 12  /
Enter value for length: 20
old   6:        length :=&length ;
new   6:        length :=20 ;
Enter value for width: 5
old   7:        width :=&width;
new   7:        width :=5;
Area of the Rectangle=100

PL/SQL procedure successfully completed.

SQL>