Therefore the volume of the solid of revolution about the x axis is Exercise c the line y 54 Step 1 To find the volume of a solid of revolution on the line y 54 use the Select 50 40 30 20 10 8748T 5 According to the Washer method Volume V 1 f R x r x dx 8748 5 The representative rectangle is shown in the figure The outer and inner radii of this solid on line y 54 are R x 54 and r x axis of revolution 6x respectively