By installing efficient water fixtures, the average american can reduce water use to about 45 gallons of water per day. using such water fixtures , about how many gallons of water would the average american use in december ?

Since there is no given average consumption of water by an average American on a daily basis. Let us just solve for the gallons of water that can be saved up by an average american in December. This can be calculated by multiplying the number of days in December which is 31 to the number of gallons of water saved up per day which is 45. The answer would be 1,395 gallons. 

A=bxh3.2x1.8=5.76 centimeters square

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.