# Circle Command in Autodesk Inventor 2011

Circle :

A **circle** is a simple shape of Euclidean geometry consisting of those points in a plane which are equidistant from a given point called the **center**. The common distance of the points of a circle from its center is called its **radius**.

Circles are simple closed curves which divide the plane into two regions, an interior and an exterior. In everyday use, the term “circle” may be used interchangeably to refer to either the boundary of the figure (also known as the **perimeter**) or to the whole figure including its interior. However, in strict technical usage, “circle” refers to the perimeter while the interior of the circle is called a **disk**. The **circumference** of a circle is the perimeter of the circle (especially when referring to its length).

A circle is a special ellipse in which the two foci are coincident. Circles are conic sections attained when a right circular cone is intersected with a plane perpendicular to the axis of the cone.

Want to know more on List of Circle Topics

Let’s get started with Circle Command in Autodesk Inventor 2011.

Use the Circle command on the Sketch tab to create circles two ways: from a center point and radius or tangent to three lines. To create a circle, select a part face or work plane to use as the sketch plane. In an empty file, the sketch plane is preset and you can start to sketch.

**To Create Center Point Circle**

- On the ribbon, click Sketch tab Draw panel Center Point Circle.
- Click in the graphics window to set the center point.
- Move the cursor to preview the circle radius and click to set.
- Continue to create circles as needed.

**To create a circle tangent to three lines**

- On the ribbon, click Sketch tab Draw panel Tangent Circle.
- Click a line to set the first tangent line for the circle.
- Click another line to set the second tangent line.
- Move the cursor over the third line to preview the circle.
- Click the third line to create the circle tangent to the three lines.
- Continue to create circles as needed.

**Insert / Draw Circles using Point Snap**

**Mid Point**: A circle can be drawn using Mid Point Option say you want a circle at the mid point of line, see figure below.

- Center Point: A Circle can be drawn using Center Point Option say you want to draw a circle inside another circle / within a arc center point / ellipse center point

- Intersection Point: A Circle can be drawn using Intersection Option, see figure below

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