horizontal line. For an oblique line, one can turn the paper so that the movement of the wrist is comfortable during drawing. When draw a short line, only wrist needs to move, while for a long line, wrist have to move together with the arm. In order to control the scale properly, squared paper can be used (3)圆的画法 drawing a circle 画圆时,应先定圆心位置,过圆心画对称中心线,在对称中心线上距圆心等 于半径处截取四点,过四点画圆即可。 To draw a circle, circle center is decided first and then symmetrical center lines are drawn passing through the center point. Pick up four points on the center lines whose dist ances to the center points are the radius of the circle. By these four points, a circle can be easily drawn 画稍大的圆时可再加一对十字线并同样截取四点,过八点画圆。 f a circle is large, one may need to pick up more points, 8 points for instance, on the center lines (4)曲线的画法 Drawing a curve 对于圆角、椭圆及圆弧连接,也是尽量利用与正方形、长方形、菱形相切的特 点画出。 Try to draw curves by keeping them tangent with some auxiliary squares, rectangles or rhombuses ◆绘制草图步骤 Steps of freehand sketching a)在图纸上定出各视图的位置 Decide the positions of viev 画出各视图的基准线、中心线。安排各视图的位置时,要考虑到各视图间应 有标注尺寸的地方,右下角留有标题栏的位置。 Draw base lines and center lines of views. Before doing this, the positions of the views should be decided, with the space left for dimensions and title barhorizontal line. For an oblique line, one can turn the paper so that the movement of the wrist is comfortable during drawing. When draw a short line, only wrist needs to move, while for a long line, wrist have to move together with the arm. In order to control the scale properly, squared paper can be used. （3）圆的画法 drawing a circle 画圆时，应先定圆心位置，过圆心画对称中心线，在对称中心线上距圆心等 于半径处截取四点，过四点画圆即可。To draw a circle, circle center is decided first and then symmetrical center lines are drawn passing through the center point. Pick up four points on the center lines whose distances to the center points are the radius of the circle. By these four points, a circle can be easily drawn. 画稍大的圆时可再加一对十字线并同样截取四点，过八点画圆。If a circle is large, one may need to pick up more points, 8 points for instance, on the center lines. （4）曲线的画法 Drawing a curve 对于圆角、椭圆及圆弧连接，也是尽量利用与正方形、长方形、菱形相切的特 点画出。Try to draw curves by keeping them tangent with some auxiliary squares, rectangles or rhombuses. ♦ 绘制草图步骤 Steps of freehand sketching a） 在图纸上定出各视图的位置 Decide the positions of views 画出各视图的基准线、中心线。安排各视图的位置时，要考虑到各视图间应 有标注尺寸的地方，右下角留有标题栏的位置。Draw base lines and center lines of views. Before doing this, the positions of the views should be decided, with the space left for dimensions and title bar