If the lines a and b in the diagram below are parallelm why do angles 2 and 6 measure 60 degree angles
because they are alternate interior angles.
because they are corresponding angles.
because they are alternate exterior angles.
because they are same-side interior angles.

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?