Mental geometry level 3

These are not interactive exercises -you need pen and paper to write your answers down.

Units of length (1) in scientific notation	Units of area (2) in scientific notation	Trigonometry	Units of volume (1) in scientific notation
Units of length (2) in scientific notation	Lines of a triangle	Volumes	Units of volume (2) in scientific notation
Pythagoras' theorem without square roots	Similar triangles	Circle, disc, cylinder, pyramid and cone	Vectors
Pythagoras' theorem with square roots	Parallel or not parallel lines?	Circle, disc, cylinder, cone, sphere
Units of area (1) in scientific notation	Enlargement and reduction