# How Do I Create and Measure Curves? (2018)

Revu can create curves on Perimeter  and Area  measurements as well as other polygon and polyline shaped markups, which include:

• Polyline
• Polyline Sketch to Scale
• Polygon
• Cloud
• Volume
• Polygon Sketch to Scale .

Because there are so many types of markups that support curves, we’ll refer to them as “polyline” below, but remember that this applies to all the markups listed above.

The easiest way to start making a curve is to create a polyline and then convert the control points (the yellow handles at each point on the polyline) or line segments to curves.

#### Converting a Line Segment to a Curve

To convert a line segment:

1. Right-click on a line segment in a polyline.
2. Click Convert to Arc .

Two new control points at the end of handlebars will display. These are how you control both the direction and the curve of the arc.

• Stretch the handlebar away from the control point to stretch the curve.
• Rotate the handlebar to change the angle of the curve as it leaves the control point.

If you convert two adjacent line segments, there will be two handles on that control point which control the curve on either side of the point. These handles can be rotated independently, allowing you to have a curve on one side of the point and a straight line on the other.

The image below shows the process of curving a polyline.  From left to right we see a polyline, the same polyline after the right line segment is converted, and finally the curves after moving the handlebars.

#### Converting a Control Point

To convert a control point:

1. Right-click on a control point.
2. Click Control Point > Convert Control Point to Curve

-or-

1. On the Control Point toolbar, click Convert Control Point to Curve
2. Click the control point you wish to curve.

-or-

• Hold the Ctrl key down and click on the control point.

Converting a control point is different from converting a line segment because the two handlebars are locked together – rotating one handle also rotates the other. This allows you to create a smooth curve on each side of this point.

The images below show the same polyline that was used above, but this time the upper right control point has been converted and the handles have been moved to change the curve.

#### Adding and Subtracting Control Points

Control points can quickly be added or removed from an existing polyline.

1. Right-click on a line segment.
2. Click Control Point > Add Control Point

– or –

• Hold the Shift key and click a line segment.
A new point will be added at the location where you click or right-click.

Subtract Control Point:

1. Right-click on a control point.
2. Click Control Point > Subtract Control Point.

-or-

• Hold the Shift key and click a control point.

#### Drawing Curves

You can also draw curves directly on the PDF rather than editing a previously existing polyline:

1. With a polyline tool activated, hold down the Ctrl key, then click and drag.
2. A new point is created when the mouse button is released.
3. Continue to click-and-drag and release to create more points.
4. Press Enter to complete the polyline.

Drawing curves is a little more complicated, so remember that you can change the curves after you finish drawing.

#### Measurements

Let’s apply this information to create an Area measurement for a freeform lawn. The image below shows the progression as an Area is created and then adjusted to match the outline.

1. Create an area with 11 points that roughly outline the shape.  Start with one at each corner and for each curve. Additional points can be created if they’re needed.
2. Create curves using Convert Control Point to Curve when a point has curves on each side and Convert to Arc when a line has an angle on one or both ends, such as the sides of the patio at the bottom.
3. Finally, move the handlebar control points to fine tune the shape of the Area until it matches the outline.