Atriangular pyramid has a volume of 840 cubic inches the triangular base has a base length of 20 inches and a height of 21 inches find the height of the pyramid

Sara goes on a slingshot ride in an amusement park. she is strapped into a spherical ball that has a radius 3*10^2 of centimeters. what is the volume of air in the spherical ball? use this formula: volume of a sphere=4/3pi,r^3 , where r is the sphere’s radius.