What is the surface area and volume?? Please help

Which sum or difference identity would you use to verify that cos (180° - ∅) = -cos ∅? a. sin (α -β) = sin α cos β – cos α sin β b. cos (α -β) = cos α cos β – sin α sin β c. cos (α -β) = cos α cos β + sin α sin β d. sin (α + β) = sin α cos β + cos α sin β

What is the first step of an indirect proof of a number that is divisible by two

The weight of an object in the water is 7% of its weight out of the water. what is the weight of a 652g object in the water?