Jeremy wants to know the density of a rock in grams per cubic centimeter.  The rock has a mass of 1.08 kilograms and a 
volume of 400 cubic centimeters.  What is the density of the rock in grams per cubic centimeter?  (g/cm³)

Line k has a slope of -5.  Line j is perpendicular to line k, and passes through the point (5,9).  Create the equation for line j.

A right triangle is shown.  What is cos A?