数学课件：用Flash AS推导三角形面积-Flash教程

[思路]

先创建一个三角形，然后复制一个并旋转移动与原图拼成一个平行四边形，平行四边形面积=底×高，所以三角形面积=底×高÷2。

[演示]

[过程]

1、创建一个影片剪辑，在帧上写如下代码：

this.createEmptyMovieClip(\"sjx0\", 1);
with (sjx0) {
lineStyle(2, 0x000000);
beginFill(0xFF0000);
moveTo(0, 0);
lineTo(0, 0);
lineTo(60, 100);
lineTo(-100, 100);
}
duplicateMovieClip(sjx0, \"sjx1\", 2);
sjx1._x = 0;
sjx1._y = 0;
my_txt.text = \"\";
sjx1.onEnterFrame = function() {
delete this.onRelease;
if (this._rotation<180) {
this._rotation = 5;
} else {
this._rotation = 0;
if (this._y<100) {
this._y = 5;
this._x = 3;
}
if (this._y == 100) {
this._y = 0;
this._x = 0;
createTextField(\"my_txt\", 3, 50, 20, 80, 20);
my_txt.text = \"点击重来\";
my_txt.selectable = false;
my_txt.autoSize = true;
my_txt.textColor = 0xFFFFFF;
this.onRelease = function() {
my_txt.text = \"\";
this._x = 0;
this._y = 0;
this._rotation = 0;
};
}
}
};

2、把上面元件拖入到主场景中合适的位置。