The tutorials in this section cover various ways to draw circular and elliptical Arcs. There are a number of construction methods that can be used to draw arcs. This makes them deserving of a separate tutorial section.
Arcs can be drawn by locating points with your cursor (mouse, stylus or your finger), entering coordinates (absolute, delta or polar), or by using the arrow keys on your keyboard. Each of these techniques is covered in Drawing lines and entering points. In the tutorials that follow you will be asked to enter points at specific coordinates. You can use whichever input technique you prefer to enter the points.
The tutorials in this section assume that you have created a full-scale metric ISO A4 size drawing and have your device in the "landscape" orientation. You can review the steps to create this drawing in the Create a full-size metric A4 drawing sheet task.
In this exercise we're simply setting the view to show an enlarged area in the center part of your drawing. All of the exercises in this section will use this view.
(60, 80) to (220, 150).
This tutorial shows two construction methods that can be used to create arcs when the center point is known.
(110, 130).
Note that a "rubber band" arrow follows the cursor with its base anchored at (110, 130).
This is the radius vector for the arc.
(110, 140) and enter a point.
Note that a rubband arc centered at (110, 130) follows the cursor.
The distance between the center point and (110, 140) defines the radius.
(110, 140), the arc sweeps counter-clockwise; if you move the cursor to the right, the arc sweeps clockwise.
Move the cursor to the left of (110, 140), then to (120, 120) and enter a point.
(110, 130).
Note that a "rubber band" arrow representing the radius vector follows the cursor with its base anchored at (110, 130).
Note also that the length of the radius vector is fixed at 9 mm.
(110, 140) (the end of the previously created arc) and enter a point.
Note that a rubband arc with a radius of 9 mm centered at (110, 130) follows the cursor.
(110, 140) (setting the arc direction to counter-clockwise), then to (120, 120) and enter a point.
You should now have a black arc filled with light gray, a radius of 9 mm, start angle at 90 degrees, and an included angle of 225 degrees.
This tutorial shows how to create arcs by specifying their radius, start angle and included angle values. With these values explicitly set, all that is needed is a center point to define the arc.
(110, 90).
Note that the arc appears immediately since only one point is required to locate the arc.
(110, 90).
A smaller arc appears concentric to the first.
(110, 90).
You should now have a thin black arc between the two previously created arcs.
This tutorial shows how to create an arc that passes through three points. We will start by drawing a line connecting the three points.
(160, 126), (140, 130) and (160, 134).
You should now have a two-segment blue line shaped like a sideways "V" pointing to the left.
(160, 126) (the first vertex of the blue line).
A circular marker should appear at this point.
(140, 130) (the second vertex of the blue line).
Another circular marker appears at this point and a rubber band arc follows the cursor passing through the previous markers and ending at the cursor.
(160, 134) (the last vertex of the blue line).
You should now have a green arc passing though each vertex of the blue line.
This tutorial shows how to create semi-circles (half circles, or arcs with an included angle of 180 degrees) by specifying diametrically opposite points.
(150, 80).
A rubber band counter-clockwise semi-circle with one endpoint anchored at (150, 80) follows the cursor.
(150, 100).
A green semi-circle should appear sweeping counter-clockwise from (150, 80) to (150, 100).
(150, 100), (150, 90), (150, 80) and (150, 90).
You should now have three semi-circles forming a green "apostrophe" shape.
This tutorial shows how to create an arc tangent to two intersecting lines (a fillet). Fillets are created by locating the three points that define the two intersecting lines. We will start by drawing lines that represent the two tangent line segments.
(204, 120), (176, 120) and (204, 140).
You should now have a two-segment cyan line connecting the three points.
(190, 120) (the mid-point of the first cyan line).
A rubber band line representing the first tangent line follows the cursor from (190, 120).
(176, 120) (the intersection of the two cyan line segments).
A rubber band line representing the second tangent line follows the cursor from (176, 120).
A rubber band arc tangent to both lines also follows the cursor.
(204, 140) (the end point of the second cyan line segment).
You should now have a blue arc tangent to the two cyan lines.
The arc is tangent to the first line segment at its mid-point (190, 120).
(190, 120) (the mid-point of the first cyan line).
A rubber band line representing the first tangent line follows the cursor from (190, 120).
(176, 120) (the intersection of the two cyan line segments).
A rubber band line representing the second tangent line follows the cursor from (176, 120)
A rubber band arc with a radius of 6 mm tangent to both lines also follows the cursor.
(204, 140) (the end point of the second cyan line segment).
You should now have a green arc with a radius of 9 mm tangent to both cyan lines.
This tutorial shows how to draw elliptical arcs. The construction methods used to draw elliptical arcs are exactly the same methods used to draw ellipses. Ellipses become elliptical arcs when the ellipse's Included angle is set to something less than 360 degrees. In this tutorial, we will draw two 2:1 semi-elliptical arcs connected by line segments. This shape could represent a pressure vessel in a Piping and Instrument Diagram (P&ID). We will start by drawing the line segments.
(180, 85), (180, 95), (200, 95) and (200, 85).
You should now have two parallel 10 mm lines 20 mm apart.
(180, 95) (the top endpoint of the left line segment).
Note that a rubber band ellipticial arc follows the cursor.
(200, 95) (the top endpoint of the right line segment).
A red semi-ellipse should connect the top endpoints of the line segments.
(200, 85) and (180, 85) (the bottom endpoints of the line segments).
You should now have a closed shape consisting of two red semi-ellipses connected by two red line segments.