Marrero has an hourglass with these dimensions on his desk. What is the volume of sand in Marrero's hourglass?

1. what is the measure of ∠abc? what is the measure of ∠abd?

He concluded that a heavier object dropped from the same height as a lighter object will land

The size of a certain cell is 2.5*10^-9m. another cell is 1.5*10^3 times larger. how large is the larger cell in scientific notation?