6th topic

Use the mouse to zoom and rotate the plan.

Move the slider to change the angle of the sloped plane.

1. By moving the slider or using the animation button, compare the distances between horizontals with a change in the angle of inclination of the plane.

2. By changing the angle of inclination of the plane, watch how the location of points on the plane changes.

3. Determine which horizontal is the projection of point A and point B.

Use the mouse to zoom and rotate planes.

Move the slider to change the angle of the sloped plane.

1. The projection of which line (1, 2, or 3) is perpendicular to the horizontals of the inclined plane?

2. Compare the lines (1, 2, and 3) on the inclined plane and determine which one is the slope line of the plane.

Use the mouse to zoom and rotate the cone.

1. Look at the top projection. Sections using horizontal planes are concentric circles. If the distances between horizontal planes are equal, the distances between the circles will also be equal.

2. Look at the front projection. Sections using vertical planes are triangles, as long as the cutting plane intersects the vertex of the cone.

Use the mouse to zoom and rotate the pyramid.

Move the slider to change the base polygon of the pyramid. 

Note the following:

1. Sections of the pyramid using horizontal planes are congruent polygons.

2. Sections of the pyramid obtained using vertical planes are triangles with different bases.