30 AutoCAD and Its Applications—Advanced Copyright Goodheart-Willcox Co., Inc. After the fi rst point is set, you can enter the Arc option. The current segment will then be created as an arc instead of a straight line. See Figure 2-11. Arc segments will be created until you enter the Line option. The suboptions for the Arc option are: • Close. If there are two or more segments, this option creates an arc segment between the active point and the fi rst point of the polysolid. You can also close straight-line segments. • Direction. Specifi es the tangent direction for the start of the arc. • Line. Returns the command to creating straight-line segments. • Second point. Locates the second point of the arc. This is not the endpoint of the segment. • Undo. Removes the previous segment of the polysolid arc. PROFESSIONAL TIP PROFESSIONAL TIP The Object option of the POLYSOLID command is a powerful tool for converting 2D objects to 3D solids. For example, you can create a single-line wall plan using a polyline and then quickly convert it to a 3D model. Pyramid A pyramid has a base composed of straight-line segments and edges that converge at a single point. The pyramid base can be composed of three to 32 sides and is drawn much like a 2D polygon. A pyramid primitive may be drawn with a pointed apex or as a frustum pyramid, which has a truncated, or fl at, apex. See Figure 2-12. Once the command is initiated, you are prompted for the center of the base or to enter an option. To set the number of sides on the base, select the Sides option. Then, enter the number of sides. You are returned to the fi rst prompt. The base of the pyramid can be drawn by either picking the center and the radius of a base circle or by picking the endpoints of one side. The default method is to pick the center. Simply specify the center and then set the radius. To pick the endpoints of one side, select the Edge option. Then, pick the fi rst endpoint of one side followed by the second endpoint. If dynamic input is on, you can also set a rotation angle for the pyramid. PYRAMID Ribbon Home Modeling Solid Primitive Pyramid Type PYRAMID PYR Straight-line segments Preview of arc segment to be drawn Arc segment Figure 2-11. The Arc option of the POLYSOLID command is used to create curved segments.