We use Strike and Dip to describe the geometry of a rock layer. To get accustomed with strike and dip measurements, some practice tools are listed here:

Misconceptions    LavaFlowTops  Strike and Dip  Eagle Harbor  Delaware Mine  Paleomagnetism   Syncline   GeoTime   Radioactive   Stromatolites    Sedimentary Structures   Alluvial Fans   Raised Shorelines