To draw two-dimensional arcs in CET, go to the Tools component tab and navigate to the 2D Arcs section. To draw arcs on a Paper, go to Paper View, enter the Drawing (paper) component tab, and locate the Arcs section. Note that double arcs function the same way as single arcs in the Paper View.

Arc Through Tangent and Angle

The Arc through tangent and angle tool draws a curve as a tangent of a line and can be a continuation of a line.

To draw an arc like the one below, follow these steps:

1. Place a straight line in your 2D view.
2. Select the Arc through tangent and angle component from the Tools component tab.
3. Move the cursor to the drawing area and click once at the right end of the line.
4. Enter the desired radius in the Radius field in the properties box, or hover your cursor at the desired radius.
5. Move the cursor horizontally to the right, until the arc’s red dashed help line forms an extension of the existing solid line.
   
   Use arrow keys to lock into a 0, 90, 180, or 270 degree angle.
6. Click once. Move the cursor below the level of the horizontal line.
7. In the properties box, the Arc angle field is selected. Enter the desired value and click, or hover your cursor at the desired angle. Then click again to complete the arc.

Arc Inside Two Tangent Lines

The Arc inside two tangent lines tool draws a curve between two lines in order to join them, see example below.

To draw such an arc, see the example below and follow these steps:

Identify two tangent lines in the drawing area and select the Arc inside two tangent lines component from the component tab. You will click four times to complete the tool, as shown in the images below.

1. Move the cursor to the drawing area and snap the arc to one of the lines. Click the arc into position.
2. Make sure that the dotted pink line forms an extension of the existing line and click again.
3. Move the mouse pointer towards the end of the other line. When the pink dotted line snaps to the end of the second line and the help text End is displayed, click again.
4. Move the pink dotted line so that it overlaps the solid line and click again.

Arc Through Three Points

The Arc through three points tool is used when three fixed points are given. See examples below.

As in the example below, if you have drawn something similar to what you see in Figure A below and would like to add an arched extension similar to the one in Figure C, follow these steps:

1. Create the middle point using a Help line. Select the Help line tool from the 2D Toolbar. Move it towards the middle of the solid line on the lower long side. A tooltip will appear when it has found the exact middle.
2. Left click and hold to set the first point of the help line when the help text Middle is displayed. Continue to hold down the mouse button and drag the help line to the desired length, or enter the Length in the Properties box. (Figure B).
   
   Use arrow keys to lock into a 0, 90, 180, or 270 degree angle.
3. Select the Arc through three points from the Component Tab. Click to place the first point of the arc at #1 in Figure D
4. Move the cursor to the middle point, which is the end of the help line (#2 in Figure D). Click to place the middle point when the help text reads End.
5. Move the mouse pointer to the last point (#3 in Figure D) and click to complete the arc.

Arc Specified by Radius and Angle

The Arc through radius and angle tool is used when the arc angle and radius are given.

To draw an arc like the one below, follow these steps:

You have drawn a rectangle and would like to round one of the corners. You know the exact dimensions of the rounding. Follow the instructions below:

1. Select the Arc through radius and angle tool from the Tools component tab. Click the center of the arc in position at the corner of the rectangle.
2. Move the cursor or enter Radius in the properties box. Click one of the arc’s fixed points on one side of the rectangle.
3. Choose the direction of the arc using the mouse and click.
4. Drag the arc out to the desired degree or enter the Arc Angle in the properties box and click it in position. Remove the corner piece using the Trim lines tool.

Use the Trim Lines tool to remove the excess lines at the corner: