What is the perimeter of a triangle having side lengths of 8 cm, 10 cm and 6 cm?

The function v(r)=4/3pir^3 can be used to find the volume of air inside a basketball given its radius. what does v(r) represent

Two cars which are 40 miles apart start moving simultaneously in the same direction with constant speeds. if the speed of the car which is behind is 56 mph and the speed of the other car is 48 mph, how many hours will it take for the car which is behind to catch up the car ahead of it?

How is this equation completed? i cannot find any examples in the book.