Example 4.9

FORTRAN Version

!
      PROGRAM P38
!
!  This program will find the perimeter and the area of a triangle
!
!
     IMPLICIT NONE
     REAL :: A,B,C,PERI,SEMI,AREA
     INTEGER :: N
!
!    Tell program where data for  READ *  is coming from
     OPEN(UNIT=5, FILE='P38.DAT')      ! UNIT=5 is the default input
!
! 
!    READ DATA
!
     DO N=1,20
        READ *,A,B,C
        IF( A == -90.0 ) STOP

        IF( A <= 0 .OR. B <= 0 .OR. C <= 0 ) THEN
          PRINT 5,A,B,C
          PRINT *,'ALL THE VALUES MUST BE POSITIVE.'
5         FORMAT(' A=',F8.3,'  B=',F8.3,' C=',F8.3)
        ELSE
          PERI = A+B+C
          SEMI = PERI/2
          AREA = SEMI * (SEMI-A) * (SEMI-B) * (SEMI-C)
          IF (AREA .LT. 0) THEN
             PRINT 5,A,B,C
             PRINT *,'TWO SIDES SHORTER THAN THIRD'
          ELSE
             PRINT 8,A,B,C,PERI,SQRT(AREA)
8            FORMAT(' A=',F8.3,' B=',F8.3,' C=',F8.3,' PERIMETER =', &
             F8.3,' AREA=',F8.3)
          END IF
        END IF
     END DO
     STOP
     END PROGRAM P38

5  7  3
5 -2 5 
34 62 54
30 5 43
-90 -90 -90

              +--------------------------------------------------+
              |     32-bit Power for Lahey Computer Systems      |
              |   Phar Lap's 386|DOS-Extender(tm) Version 7.0    |
              |  Copyright (C) 1986-94 Phar Lap Software, Inc.   |
              |           Available Memory = 14880 Kb            |
              +--------------------------------------------------+


A=   5.000 B=   7.000 C=   3.000 PERIMETER =  15.000 AREA=   6.495
A=   5.000  B=  -2.000 C=   5.000
ALL THE VALUES MUST BE POSITIVE.
A=  34.000 B=  62.000 C=  54.000 PERIMETER = 150.000 AREA= 916.229
A=  30.000  B=   5.000 C=  43.000
TWO SIDES SHORTER THAN THIRD

Pascal Version

PROGRAM p48 (input, output);
{
     Program to calculate circumference, area, and volume
     given a radius
}
VAR
  pi, circum, area, vol, r : REAL;
  n : INTEGER;
BEGIN
  writeln ( ^l );
  writeln ( ' ':7, 'rad', ' ':5, 'cir', ' ':5, 'area', ' ':5, 'vol' );

  pi := 3.14159;

  readln ( n );

  r := 1;
  WHILE ( r <= n ) DO
    BEGIN
      circum := 2.0 * pi * r;
      area := pi * sqr(r);
      vol := ( 4.0 / 3.0 ) * pi * r * r * r;
      writeln ( r:9:2, circum:9:2, area:9:2, vol:9:2 );
      r := r + 0.5
    END; { end while }
  writeln ( ^l )
END.

7

Last modified: 21/07/97