More Pinwheels

Revised 1.5.06

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Animated Spinwheels around a Point of Rotation

Start with a new sketch.
Go to the File menu and choose New Sketch.

Turn off automatic point labeling.
Go to the Display menu and choose Preferences. Make sure that Autoshow points is not checked. If it is, click on the check to make it go away

Draw a triangle.
Use the line segment tool to draw a triangle.

Highlight the vertices of the triangle.
Choose the select button. Click on and highlight one of the vertices. Hold the shift key down and highlight the other two vertices so all three are highlighted.

Make a triangle interior.
With the three points highlighted, go to the construct menu and choose Polygon Interior.

Add color to your triangle.
At this time your triangle should be "shimmering". That means that it is highlighted. Right click your mouse and choose a color. Click in any white area to turn off the highlighting. You should see a colorful triangle.

Make a point of rotation outside of the triangle.
Make a point outside the triangle. Double click on it. You should see an exploding “doughnut” effect. This means your point is now a point of rotation.

Highlight the triangle.
Point your mouse outside your triangle and click in the white area to deselect the points. Click inside the triangle to select the interior. The interior should now be highlighted (shimmering.)

Rotate the interior of your highlighted triangle.
Go to the transform menu and choose rotate.
Enter 60 degrees.
Click OK.
Go back and choose rotate again. Continue until you have “completed” the pinwheel. Go back and change the colors of each triangle.

Test your spinwheel.
Click on any vertex and drag it around.
You should notice that all the shapes change.

Animate the spinwheel.
Draw a circle anywhere on your sketch.
Choose (highlight) a vertex of one of your triangle.
Hold the shift key down and highlight the circle. (You now have a point and a path highlighted.)

Make an animation button.
Go to the Edit menu and choose the action button followed by animation.
Click on animate and you will see an animate button appear.

Do the animation.
Double click on the button and your animation should begin. Just click anywhere on the screen to stop.
Move the circle to another place. Make it smaller. Animate it again. Hide the circle and animate it again.

Some Questions to answer (and hand in to your teacher.)
1. Repeat this activity with other angles of rotation like 90, 120, 45, and 30.

2. How many triangles does it take to complete the spinwheel if the angle is 90? Why?

3. How many triangles does it take to complete the spinwheel if the angle is 120? Why?

4. How many triangles does it take to complete the spinwheel if the angle is 30? Why?

5. How many triangles does it take to complete the spinwheel if the angle is 45? Why?

6. Print out your favorite spinwheel!