Tilt plane

Tilt the plane in this movie of a plane (layer) intersecting topography. 

Can you tell which way the layer is dipping by how the plane intersects the contours along the red line? 

Can you determine how much the plane is dipping (horizontal, gentle, moderate, steep, or vertical) by how the red line traces across the contours?  

Discuss with your partner all the observations you might use to determine in which direction the plane is dipping and by how much.