# pretty print from autoindent and ased editor
        # Brahmagupta Area of Cyclic Quadrilateral calculator
        # written on Windows XP on eTCL
        # working under TCL version 8.6
        # gold on TCL, 15dec2016
        package require Tk
        package require math::numtheory
        namespace path {::tcl::mathop ::tcl::mathfunc math::numtheory }
        set tcl_precision 17
        frame .frame -relief flat -bg aquamarine4
        pack .frame -side top -fill y -anchor center
        set names {{} {side a meters :} }
        lappend names {side b meters:}
        lappend names {side c meters: }
        lappend names {side d meters: }
        lappend names {optional:}
        lappend names {answers: quad semiperimeter meters : }
        lappend names {quad perimeter meters : }
        lappend names {cyclic_quad_area meters squared:}
        foreach i {1 2 3 4 5 6 7 8} {
            label .frame.label$i -text [lindex $names $i] -anchor e
            entry .frame.entry$i -width 35 -textvariable side$i
            grid .frame.label$i .frame.entry$i -sticky ew -pady 2 -padx 1 }
        proc about {} {
            set msg "Calculator for Brahmagupta Area of Cyclic Quadrilateral V2
            from TCL,
            # gold on TCL WIKI, 15dec2016 "
            tk_messageBox -title "About" -message $msg }
        proc self_help {} {
            set msg "Brahmagupta Area of Cyclic Quadrilateral V2
            from TCL ,
            # self help listing
            # problem, Brahmagupta Area of Cyclic Quadrilateral V2
            # 4 givens follow.
            1) side a meters :
            2) side b meters :
            3) side c meters :
            4) side d meters :
            # Recommended procedure is push testcase and fill frame,
            # change first three entries etc, push solve,
            # and then push report. Report allows copy and paste
            # from console to conventional texteditor. For testcases
            # testcase number is internal to the calculator and
            # will not be printed until the report button is pushed
            # for the current result numbers.
            # >>> copyright notice <<<
            # This posting, screenshots, and TCL source code is
            # copyrighted under the TCL/TK license terms.
            # Editorial rights and disclaimers
            # retained under the TCL/TK license terms
            # and will be defended as necessary in court.
            Conventional text editor formulas or  grabbed from internet
            screens can be pasted into green console.
            # gold on  TCL Club, 2Dec2018 "
            tk_messageBox -title "Self_Help" -message $msg }
        proc calculate {     } {
            global answer2
            global side1 side2 side3 side4 side5
            global side6 side7 side8
            global testcase_number
            incr testcase_number
            set side1 [* $side1 1. ]
            set side2 [* $side2 1. ]
            set side3 [* $side3 1. ]
            set side4 [* $side4 1. ]
            set side5 [* $side5 1. ]
            set side6 [* $side6 1. ]
            set side7 [* $side7 1. ]
            set side8 [* $side8 1. ]
            set perimeter [+ $side1 $side2 $side3 $side4 ]
            set semip [* $perimeter .5 ]
            set cyclic_quad_area [sqrt [* [- $semip $side1 ] [- $semip $side2 ] [- $semip $side3 ] [- $semip $side4 ]]]
            set side7 $perimeter
            set side8 $cyclic_quad_area
        }
        proc fillup { aa bb cc dd ee ff gg hh} {
            .frame.entry1 insert 0 "$aa"
            .frame.entry2 insert 0 "$bb"
            .frame.entry3 insert 0 "$cc"
            .frame.entry4 insert 0 "$dd"
            .frame.entry5 insert 0 "$ee"
            .frame.entry6 insert 0 "$ff"
            .frame.entry7 insert 0 "$gg"
            .frame.entry8 insert 0 "$hh"
        }
        proc clearx {} {
            foreach i {1 2 3 4 5 6 7 8 } {
                .frame.entry$i delete 0 end } }
        proc reportx {} {
            global side1 side2 side3 side4 side5
            global side6 side7 side8
            global testcase_number
            console show;
            console eval {.console config -bg palegreen}
            console eval {.console config -font {fixed 20 bold}}
            console eval {wm geometry . 40x20}
            console eval {wm title . " Brahmagupta Area of Cyclic Quadrilateral  Report   , screen grab and paste from console 2 to texteditor"}
            console eval {. configure -background orange -highlightcolor brown -relief raised -border 30}
            puts "%|table $testcase_number|printed in| tcl wiki format|% "
            puts "&| quantity| value| comment, if any|& "
            puts "&| $testcase_number:|testcase_number | |&"
            puts "&| $side1 :|side a meters|   |&"
            puts "&| $side2 :|side b meters   | |& "
            puts "&| $side3 :|side c meters | |& "
            puts "&| $side4 :|side d meters | |&"
            puts "&| $side5 :|optional | |&"
            puts "&| $side6 :|answers: semiperimeter  meters |  |&"
            puts "&| $side7 :|cyclic quad perimeter meters  |  |&"
            puts "&| $side8 :|cyclic_quad_area meters squared |  |&"
        }
        frame .buttons -bg aquamarine4
        ::ttk::button .calculator -text "Solve" -command { calculate   }
        ::ttk::button .test2 -text "Testcase1" -command {clearx;fillup 1.0 1.  1.0 1.0  1.0  2. 4. 1.}
        ::ttk::button .test3 -text "Testcase2" -command {clearx;fillup 2.0 2.0 2.0 2.0  1.0  4. 8. 4. }
        ::ttk::button .test4 -text "Testcase3" -command {clearx;fillup 3.0 3.  3.0 3.0  1.0  6. 12. 9. }
        ::ttk::button .clearallx -text clear -command {clearx }
        ::ttk::button .about -text about -command {about}
        ::ttk::button .self_help -text self_help -command { self_help }
        ::ttk::button .cons -text report -command { reportx }
        ::ttk::button .exit -text exit -command {exit}
        pack .calculator  -in .buttons -side top -padx 10 -pady 5
        pack  .clearallx .cons .self_help .about .exit .test4 .test3 .test2   -side bottom -in .buttons
        grid .frame .buttons -sticky ns -pady {0 10}
        . configure -background aquamarine4 -highlightcolor brown -relief raised -border 30
        wm title . "Brahmagupta Area of Cyclic Quadrilateral Calculator V2"  

  puts " %| testcase $testcase_number | value| units |comment |%"
  puts " &| volume| $volume| cubic meters |based on length $side1 and width $side2   |&"