Marty drew a model of the school library. The total area of the floor is 132 square centimeters. What is the area of the shaded part of the model shown below?
10 centimeters
6 centimeters

What is the total area of the figure?

Which of the following parabolas opens down?

The weight of a radioactive isotope was 96 grams at the start of an experiment. after one hour, the weight of the isotope was half of its initial weight. after two hours, the weight of the isotope was half of its weight the previous hour. if this pattern continues, which of the following graphs represents the weight of the radioactive isotope over time? a. graph w b. graph x c. graph y d. graph z