How does a geometric artboard draw a semicircle?

Draw a circle in the Geometry palette, you may, if you make a semicircle, you may not have made it! How does a geometric artboard draw a semicircle? The following small series to introduce the next geometric sketchpad painting semicircle Tutorial.

Analysis: In a circle of the same arc in the circumference of the angle is half, according to the theorem, the circular angle of the semicircle is a good 90°, so we can make a right triangle to make semicircle.

The specific steps are as follows:

1. Open the Geometry artboard, click the "Custom Tool"--"triangle"-"Right triangle", click on the canvas above the mouse, and then drag the mouse to draw a right-angled triangle.

Using the custom tool to draw a right-angled triangle example

2. Use the move Arrow tool to select the three vertices of the right-angled triangle, click "Construct" on the menu bar--the arc over three points, and get the figure shown below.

Example of an arc with three points constructed over three vertices of a right-angled triangle

3. Select the two rectangular edges of the triangle and right-click to select "Hidden segment" so that the semicircle is made, as shown in the following figure.

Select right triangle two right side to execute hidden command

The above to explain the use of geometric artboards to make semicircle method, mainly in the semicircle of the nature of the understanding, and then there are targeted drawings.

The Round table is a kind of above small big three-dimensional figure, in the geometry sketchpad inside how can the fastest produce round Taiwan? Let's take a look at the method of making the circular table of the geometrical sketchpad.

First, draw the round table

1. Open the Geometry artboard, click the sidebar "Custom Tool"-"solid geometry"-round table.

Select "Custom Tool"--"solid geometry"--"Round Table" sample

2. Use the mouse in the blank position to determine the round center of the bottom of the circle, with the mouse to adjust the size and direction of the Round table and then click the mouse to draw a round table.

Using the Geometry Artboard custom tool to draw a round table sample

Second, adjust the round table

1. Adjust the size and direction of the round Table

Press and hold the center of the bottom circle red dot to drag, you can adjust the size of the bottom circle to adjust the size of the round table, and through rotation to adjust the direction of the round table.

Drag the center of the bottom circle to adjust the size and orientation of the round Table

2. Adjust the position of the round table

You can adjust the horizontal and vertical position of the round table by holding down any line above it and dragging it up or down.

Drag the line above the round table to adjust the position of the round table

Third, beautify the round table

At this point, the round table looks like there are some extra lines. We select these lines and click the right button to select "Hidden segments" to remove them. At this point there is less than a line on the right side, we can call the line line ruler tool to draw a thread.

Hide unnecessary objects and construct segments to beautify the round table.

Let's take a look at how to measure the radius of a circle with a geometric artboard.

The specific steps are as follows:

First, draw a circle

Open the Geometry artboard, click the "Point tool" on the left sidebar, draw two points above the geometry artboard as a point on the center and circumference of the circle, and the distance between two points is the radius;

Example of using the Point tool to draw the center and circumference points of a circle

Click the sidebar Move Arrow tool to select the two points you just drawn and click on the menu bar "construct"--to draw a circle around the center and circle, you can see that a circle is drawn, as shown in the following figure.

Example of drawing a circle with center and Circle points

Second, measuring radius

Select the sidebar Move Arrow tool to select a circle, click Measure on the menu bar-radius, and you can see the radius of the circle on the canvas, as shown in the following figure.

Select Circle to perform metric--radius metric circle radius

Now let's take a look at the method for measuring the circumference of a geometric artboard

First, draw a circle

Open the Geometry artboard, click the side Bar Circle tool, click on the canvas to determine the center of the circle and move the mouse to determine the radius and draw a circle.

To draw a circle using the Circle tool in a Geometry artboard sample

Second, the measurement perimeter

1. Select the sidebar "Move Arrow Tool", select the entire Circle, click the menu bar "metric"-"circumference length";

Select a circle to perform a measure--example of a "circumference long" command

2. Then we can see that the circumference of the circle has already appeared on the canvas, as shown in the following figure.

Example of a circumference long data display on a canvas