Geometria básica no plano: áreas e perímetros: Difference between revisions
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<jsxgraph box="box"> | <jsxgraph box="box"> | ||
var board = JXG.JSXGraph.initBoard('box', {boundingbox: [-5, 5, 5, -5], axis:true}); | var board = JXG.JSXGraph.initBoard('box', {boundingbox: [-5, 5, 5, -5], axis:true}); | ||
var po = board. | var po = board.create('point',[0,0], {name:'O',style:5,fixed:true}); | ||
var pa = board. | var pa = board.create('point',[2,2], {name:'A',style:5}); | ||
var pb = board. | var pb = board.create('point',["X(A)",0], {name:'B',style:5}); | ||
var t = board. | var t = board.create('polygon',["O","A","B"]); | ||
var tarea = board. | var tarea = board.create('text',[3,2.0,function(){area = 0.5*Math.abs(pa.Y()*pb.X());return "área = "+area.toFixed(6);}]); | ||
var tperi = board. | var tperi = board.create('text',[2.45,2.5,function(){ | ||
b = Math.abs(pa.X()); h = Math.abs(pa.Y()); | b = Math.abs(pa.X()); h = Math.abs(pa.Y()); | ||
p = b+h+Math.sqrt(b*b+h*h);return "perímetro = "+p.toFixed(6);}]); | p = b+h+Math.sqrt(b*b+h*h);return "perímetro = "+p.toFixed(6);}]); | ||
var h = board. | var h = board.create('text',[3.35,3.50,function(){altura=Math.abs(pa.Y());return "h = "+altura.toFixed(6);}]); | ||
var b = board. | var b = board.create('text',[3.35,3.00,function(){base =Math.abs(pa.X());return "b = "+base.toFixed(6);}]); | ||
</jsxgraph> | </jsxgraph> | ||
Line 33: | Line 33: | ||
<jsxgraph box="box2"> | <jsxgraph box="box2"> | ||
var board = JXG.JSXGraph.initBoard('box2', {boundingbox: [-5, 5, 5, -5], axis:true}); | var board = JXG.JSXGraph.initBoard('box2', {boundingbox: [-5, 5, 5, -5], keepAspectRatio:true, axis:true}); | ||
var l1s = board. | var l1s = board.create('line', [[0,0], [1,1]],{strokeWidth:0}); | ||
var pas = board. | var pas = board.create('point',[2,2], {name:'A',style:5,slideObject:l1s}); | ||
var pbs = board. | var pbs = board.create('point',["X(A)" ,"-Y(A)"], {name:'B',style:5}); | ||
var pcs = board. | var pcs = board.create('point',["-X(A)","-Y(A)"], {name:'C',style:5}); | ||
var pds = board. | var pds = board.create('point',["-X(A)","Y(A)" ], {name:'D',style:5}); | ||
var s = board. | var s = board.create('polygon',["A","B","C","D"]); | ||
var sarea = board. | var sarea = board.create('text',[3 ,2.5,function(){side=2*Math.abs(pas.X());area = side*side;return "área = "+area.toFixed(6);}]); | ||
var speri = board. | var speri = board.create('text',[2.45,3.0,function(){side=2*Math.abs(pas.X());peri = 4*side ;return "perímetro = "+peri.toFixed(6);}]); | ||
var a = board. | var a = board.create('text',[3.40,3.5,function(){side=2*Math.abs(pas.X());return "a = "+side.toFixed(6);}]); | ||
</jsxgraph> | </jsxgraph> | ||
Line 57: | Line 57: | ||
<jsxgraph box="box3"> | <jsxgraph box="box3"> | ||
var board = JXG.JSXGraph.initBoard('box3', {boundingbox: [-5, 5, 5, -5], axis:true}); | var board = JXG.JSXGraph.initBoard('box3', {boundingbox: [-5, 5, 5, -5], axis:true}); | ||
var par = board. | var par = board.create('point',[2,2], {name:'A',style:5}); | ||
var pbr = board. | var pbr = board.create('point',["X(A)" ,"-Y(A)"], {name:'B',style:5}); | ||
var pcr = board. | var pcr = board.create('point',["-X(A)","-Y(A)"], {name:'C',style:5}); | ||
var pdr = board. | var pdr = board.create('point',["-X(A)","Y(A)" ], {name:'D',style:5}); | ||
var r = board. | var r = board.create('polygon',["A","B","C","D"]); | ||
var rperi = board. | var rperi = board.create('text',[2.45,2.5,function(){ | ||
sidea=Math.abs(par.X()); | sidea=Math.abs(par.X()); | ||
sideb=Math.abs(par.Y()); | sideb=Math.abs(par.Y()); | ||
Line 72: | Line 72: | ||
area = sidea*sideb; | area = sidea*sideb; | ||
return "área = "+area.toFixed(6);}]); | return "área = "+area.toFixed(6);}]); | ||
var ar = board. | var ar = board.create('text',[3.35,3.50,function(){sidea=2*Math.abs(par.X());return "a = "+sidea.toFixed(6);}]); | ||
var br = board. | var br = board.create('text',[3.35,3.00,function(){sideb=2*Math.abs(par.Y());return "b = "+sideb.toFixed(6);}]); | ||
</jsxgraph> | </jsxgraph> | ||
Line 88: | Line 88: | ||
<jsxgraph box="box4"> | <jsxgraph box="box4"> | ||
var board = JXG.JSXGraph.initBoard('box4', {boundingbox: [-5, 5, 5, -5], axis:true, keepAspectRatio:true}); | var board = JXG.JSXGraph.initBoard('box4', {boundingbox: [-5, 5, 5, -5], axis:true, keepAspectRatio:true}); | ||
var poc = board. | var poc = board.create('point',[0,0], {name:'O',style:5,fixed:true}); | ||
var prc = board. | var prc = board.create('point',[2,2], {name:'P',style:5}); | ||
var c = board. | var c = board.create('circle',[[0,0], ["X(P)","Y(P)"]], | ||
{strokeColor:'#0000ff',strokeWidth:3,fillColor:'#cccccc',fillOpacity:0.3}); | {strokeColor:'#0000ff',strokeWidth:3,fillColor:'#cccccc',fillOpacity:0.3}); | ||
var vr = board. | var vr = board.create('line',["O","P"], | ||
{strokeColor:'#0000ff',strokeWidth:3,straightFirst:false,straightLast:false,firstArrow:true,lastArrow:true}); | {strokeColor:'#0000ff',strokeWidth:3,straightFirst:false,straightLast:false,firstArrow:true,lastArrow:true}); | ||
var carea = board. | var carea = board.create('text',[2.6,2.5, | ||
function(){radius=Math.sqrt(prc.X()*prc.X()+prc.Y()*prc.Y());area = Math.PI*radius*radius;return "área = "+area.toFixed(6);}]); | function(){radius=Math.sqrt(prc.X()*prc.X()+prc.Y()*prc.Y());area = Math.PI*radius*radius;return "área = "+area.toFixed(6);}]); | ||
var r = board. | var r = board.create('text',[2.95,3.50, | ||
function(){radius=Math.sqrt(prc.X()*prc.X()+prc.Y()*prc.Y());return "r = "+radius.toFixed(6);}]); | function(){radius=Math.sqrt(prc.X()*prc.X()+prc.Y()*prc.Y());return "r = "+radius.toFixed(6);}]); | ||
var cperim = board. | var cperim = board.create('text',[2,3.00, | ||
function(){radius=Math.sqrt(prc.X()*prc.X()+prc.Y()*prc.Y());perimeter=2*Math.PI*radius;return "perímetro = "+perimeter.toFixed(6);}]); | function(){radius=Math.sqrt(prc.X()*prc.X()+prc.Y()*prc.Y());perimeter=2*Math.PI*radius;return "perímetro = "+perimeter.toFixed(6);}]); | ||
</jsxgraph> | </jsxgraph> |
Latest revision as of 10:56, 23 June 2021
- Triângulo rectângulo: b = base, h = altura, logo área = ( b × h )/2 e perímetro = b + h + (b2+h2)1/2. Arraste o ponto A para ver a variação do perímetro e da área com a variação da base e da altura:
- Quadrado: a = lado (ou aresta), logo área = a2 e perímetro = 4a. Arraste o ponto A para ver a variação do perímetro e da área com a variação da aresta:
- Rectangulo: a = lado 1, b = lado 2, logo área = a×b e perímetro = 2a + 2b. Arraste o ponto A para ver a variação do perímetro e da área com a variação dos lados:
- Círculo: r = raio do círculo, logo área = πr2 e perímetro = 2πr. Arraste o ponto P para ver a variação do perímetro da circunferência e da área do círculo com a variação do raio:
Última alteração em 23/07/2009
Todos os gráficos interactivos foram criados com recurso à livraria JSXGraph.