Pls the first step for finding the volume of a prism is to find the area of the base. how is this step different for rectangular prisms and triangular prisms?

Camille is preparing for her english test by typing up the notes she recorded in the margins of her 98-page workbook. she already started typing her notes, and got through the first 14 pages. if camille types for x hours at a rate of 21 pages per hour, which equation represents the number of pages she has typed, and how many hours will it take to complete the task?