Idon't understand ratios. will someone explain them?

What is the range of this function? all real numbers such that y ≤ 40 all real numbers such that y ≥ 0 all real numbers such that 0 ≤ y ≤ 40 all real numbers such that 37.75 ≤ y ≤ 40

Name the most appropriate metric unit for each measurement like the mass of cow

Which best explains why this triangle is or is not a right triangle?