Triangular pyramid is a common three-dimensional figure in geometric figures, and it is often necessary to rotate it in study and work. PHP editor Yuzai learned that in the geometric sketchpad, it is not complicated to realize the rotation operation of the triangular vertebra. This article will introduce the specific steps in detail to help everyone easily master this technique. Read on to learn how to rotate a triangular pyramid in Geometry Sketchpad.
1. Use the circle tool to draw two concentric circles with center A. Use the point tool to pick one B and C on the two circles. Draw any points D and E on the circumference of the large circle, draw line segments AD and AE, and intersect the small circle at points F and G respectively.
2. Double-click point A and mark A as the center of rotation. Select points E and G, select the [Transform]-[Rotate] command, and set the fixed angle to 120 degrees. Click [OK]. Make the same transformation for points E’ and G’.
3. Select points E, E', E'' and line segment AD, select the [Construction]-[Vertical Line] command, set the three vertical lines as dotted lines, and name them respectively j,k,i.
4. Select points G, G', G'' and line segment AD, select [Construction] - [Parallel Lines] command, set the three vertical lines as dotted lines, and name them respectively m, n, o.
5. Draw the intersection H of straight lines j and m, the intersection I of o and k, and the intersection J of l and n. Select points I, J, H and select [Construction] ——[Line Segment], set the line type to [Solid Line]. Hide the three perpendicular lines and the three parallel lines, as well as the points G, G’, G’’, E’, and E’’.
6. Select point A and line segment AD, select the [Construction]-[Vertical Line] command, and pick any point O on this vertical line. Then hide this line. Use the line segment tool to draw line segments OH, OI, OJ, and OA, where OA is a dotted line.
7. Select point E, select [Edit]-[Operation Button]-[Animation] command, set the direction to [Counterclockwise], the speed to [Medium], and move the button The label changes to [Rotate]. Just hide the line segment AD, line segment AE, point D, point E, point C, point B and the large circle.
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