How to draw an ellipse on a geometric artboard

How does a geometric artboard draw an ellipse? The geometric sketchpad is a dynamic geometric tool which is suitable for the vector analysis, drawing and function drawing of mathematics, plane geometry and physics. This tool can draw various types of graphics, here the triple Small series to bring you a tutorial to teach you how to draw an ellipse, hope to help.

The distance of one to two points and equal to the fixed length.

Open the Geometry artboard, select Show-> parameter selection, draw a check mark in the box before P point in the Automatic Selection tab bar, and then OK.

Select the Segment tool to make a segment AB in the drawing board (long axis length 2a of the ellipse for segment AB). Use the "point" tool in the line to take a point C, hold down the SHIFT key to select the A,c point, select the "transform"-> mark Vector "A->c".

Then use the "dot" tool to take a little bit of D, select D, select "Transform"-> "translate", select "m by Mark Vector" (Figure 1), then determine, will get point d '.

The Translation dialog box for fig. 1

Hold down the SHIFT key, select points D and d ', and choose "->" to draw a circle at the center and Circle Point, select d ', and press ctrl+h to hide it.

Hold down the SHIFT key, select the B,c point, and select "transform"-> "tag vector" B->c "".

Use a point tool to do a little bit of e so that its distance from the D point is less than the length of the segment AB (the length of the Segment de is 2c), select Point E, select "Transform"-> "translate", select "m by Mark Vector", and then OK, get point e '.

Hold down the SHIFT key, select the points E and E ', and select '-> ' to draw a circle on the center and Circle points, select Dot e ' and press Ctrl+h to hide it.

Hold down the SHIFT key and select the two circle circles, select "Draw"-> "intersection" (or press the Ctrl+i key) to make the intersection F and G.

The following can be divided into two directions:

1. Hold down the SHIFT key, select the point F and Point C, choose "Mapping"-> "trajectory", make the upper part of the ellipse, and then select the point G and Point C to make the lower part of the ellipse (Figure 2).

Figure 2 Ellipse

Finish, save and exit.

2. Hold down the SHIFT key, select the point F, choose "Show"-> "Tracking Point", also select the point G and Point C, select "Show"-> "Tracking point."

Hold down SHIFT to select Points C and segment AB, select "Edit"-> "Action class button"-> "Animation", pop-up "Matching path" dialog box, select "Two-way", "along line segment J", "Slowly", press the "animation" button to complete the setup. An animation button appears on the drawing pad, and an ellipse is automatically drawn when you double-click the animation button.

Finish, save and exit.

Second, concentric circle method. (Download the courseware 3 download the courseware 4)

Select "File"-> "New Drawing", select "chart"-> "Build axis", using "circle" tool as the origin of the two concentric circles (the length of the outer circle is the final ellipse of the long half axis length A, the length of the inner circle is the final ellipse of the short half axis length b), select point B and the circumference of points C and D, press CTRL The +h key is hidden.

Select "Show"-> "line"-> "dotted line", take a little bit e on the outer circle, hold down SHIFT, select Midpoint A and point E, press Ctrl+l to make the segment AE, select the segment AE and the circular circumference, press the Ctrl+i key to make the intersection F.

Hold down the SHIFT key, select the midpoint e and the vertical axis, choose "Draw"-> "parallel", make a straight line, select the midpoint f and the horizontal axis, choose "Drawing"-> "parallel", make another line.

Select both lines and press the Ctrl+i key to make the intersection point G (Figure 3).

Fig. 3 Make the intersection point G

The following can be divided into two directions:

1. Select "Show"-> "line"-> "thin lines", while selecting Point E on the intersection G and Outer circle circle, select "Drawing"-> "trajectory" to make the ellipse (Figure 4).

Fig. 4 ellipse made by concentric circle method

Finish, save and exit.

2. Select "Show"-> "line"-> "thin", select point g, select "Show"-> "Tracking point."

Hold down the SHIFT key while selecting the dot E and outer circle on the circular circumference of the Chinese and foreign circles. Select the edit-> Action class button-> animation, pop-up the Match Path dialog box, select One-way, round c2, fast, press the "animation" button to determine.

An animation button appears on the drawing pad, and an ellipse is automatically drawn when you double-click the animation button.

Finish, save and exit.

Three, single circle method.

Open a new Drawing pad, select the Circle tool to make a circle (the radius of the circle is 2a), select point B on the circumference, press Ctrl+h to hide.

Optionally, within a circle, C (A,c is the intersection of the ellipse).

Take a little d in the circle, select the midpoint C and Point D, and press Ctrl+l to make the segment CD. Select the Segment CD, press CTRL+M to make the CD midpoint e, and then select the midpoint e and Segment CD, choose "Draw"-> "vertical", make the vertical K.

Select Midpoint A and point D at the same time and press Ctrl+l key for segment AD. Select Perpendicular bisector k and segment ad at the same time, press Ctrl+i key to make intersection F (Figure 1), think about, point f the distance between a and point C is not fixed value.

Fig. 1 Single circle method for Ellipse

Select Point F, press Ctrl+t to track point F. Select the point D and circumference, select the Edit-> Action class button-> animation, pop-up the Match Path dialog box, select One-way, round C1, normal, press the animation button to complete the setup. An "animation" button appears on the drawing pad, and when you double-click the animation button, the ellipse is automatically drawn (see Figure 2).

Figure 2 automatically draws an ellipse

Alternatively, you can select the midpoint f and Point D, and you can also make the ellipse by selecting the "->" trajectory.

Finish, save and exit.

Four, the guideline method. (Download the Courseware)

Open a new Drawing pad and choose chart-> to create an axis.

Using the Segment tool as a segment CD, take a little E on the segment CD. At the same time select the midpoint C and point E, choose "Metric"-> "distance", measuring the length of the CE. Also measure the length of the CD.

Hold down the SHIFT key and select the amount of distance between the CE and CD, press the right mouse button to eject the dialog box, and select "Metric"-> "calculation" (Figure 3).

Figure 3 A way to open a calculator

Select the value-> distance (c to e) in the Open calculator (Figure 4).

Figure 4 Use of calculators

Select/-> distance (c to D) "-> OK". The ratio of CE to CD appears on the drawing board. Double-click the value with the Text tool, pop-up the Measure Format dialog box, and select T text Format (Figure 5).

Figure 5 Measure Format dialog box

Change "distance (c to e)/distance (c to D)" to "E" to determine, complete the changes.

Select point B, press Ctrl+h to hide, and take a point F (f) as the focus of the ellipse on the x axis.

For the segment GH, the point I. Use the above method to measure the distance of GI and change its distance name to C. Select the values for C and E, open the calculator, and find the C divided by the value of E, and change its name to a.

Select the calculated value of a, select chart-> draw measure, and eject the Draw Measure dialog box (Figure 6). Select "H on the transverse (x) axis" and make a straight line perpendicular to the x axis.

Figure 6 Plotting a measure dialog box

Select the measure for C, select "Transform"-> "Mark Distance", select the f point, select "Transform"-> "translate", pop the "Pan" dialog box, select "Distance by Mark" (Figure 7), OK, make point F translation point F '.

Figure 7 Translation dialog box

Successively select the point F and Point F ', select "Drawing"-> "to Circle Center and Circle point to draw round."

Select the circle and the above line perpendicular to the x axis, and press Ctrl+i to draw the intersection J and K (Figure 8).

Figure 8 Draw the intersection of the circle and the line

Select the dot J and Point K and choose "Show"-> "Tracking point".

Select point I and Line GH, select "Edit"-> "Action class button"-> "Animation", pop-up "Matching path" dialog box, select "Bidirectional", "along line segment N", "Slowly", press the "animation" button to complete the setup. An "animation" button appears on the drawing pad, and when you double-click the animation button, the ellipse is automatically drawn (see Figure 9).

Figure 9 automatically draws an ellipse

Select the values for CE, CD, E, C, and a, and press Ctrl+h to hide.

Finish, save and exit.