please explain the formula used to find the volume (using Matlab)

A fuel tank is made of a half cylinder ( as shown. Derive an expression for the amount of fuel in gallons as a function of h. Create a vector for h ranging from 0 to 14 in. with increments of 2 in. Then calculate the corresponding volume rounded to the nearest tenth of a gallon. Display the results in a two-column table where in the first column are the values of h and in the second column the associated val- ues of volume (in gallons). 5, 14 in.)