The sum of the measures of the angles of a parallelogram is 360°. In the parallelogram on the right, angles A and D have the same measure as well as angles C and B. If the measure of angle C is four times the measure of angle A, find the measure of each angle.

sample answer: you can determine whether each element of the domain is paired with exactly one element of the range. for example, if given a graph, you could use the vertical line test; if a vertical line intersects the graph more than once, then the relation that the graph represents is not a function.