Find the lateral (side) surface area of the cone generated by revolving the line segment y equals one fourth x , 0 less than o
r equals x less than or equals 7, about the x-axis. The lateral surface area of the cone generated by revolving the line segment y equals one fourth x , 0 less than or equals x less than or equals 7, about the x-axis is nothing. (Type an exact answer, using pi as needed.)