Which angles are complementary?

Rose bought a new hat when she was on vacation. the following formula describes the percent sales tax rose paid b=t-c/c

Asap! i need this done today and i really don’t understand it. some one ! will mark

The formula for finding volume of a cone 1/3pi x r^2h. the volume of a cone is 300 cm^3 and the height of the cone is 10 what is the approximate radius of the cone