Rectangular Solid
Learn the concepts behind volume and surface area before you start solving GMAT Solid geometry problems. All solid geometry problems come down to this - length, breadth and height. For data sufficiency questions, look out for values of l, b and h. if any of them are missing then it would be easy to eliminate answer choices.
6 rectangular faces constitute a rectangular solid
The formulas you need to remember for a rectangular solid are
Volume = Length (l) x Width (w) x Height (h)
Surface Area = (2 x Length x Width) + (2 x Length x Height) + (2 x Width x Height)
"If length = width = height, that means that the rectangular solid is, in fact, a cube."
Terminologies
Vertex: Wow! quite a confusing word? Not really
Vertex = Corner
a) Vertex is the number of corners in a figure
The rectangular solid above has 8 vertices (plural of vertex), can you identify them?
b) Edge is the number of lines that you see in a diagram.
The edge is simply the lines you see in the diagram above: the line where two surfaces meet.
Cylinder
Questions that has cylinder in it are much easier. You have to focus on only two values - the radius(r) and the height(h).
If you don’t know the radius, anything that enables you to determine the radius, such as the diameter (radius = diameter / 2) or the circumference (radius = circumference / 2pi) will suffice.
Regarding cylinders, the formulas you need to know are
Volume = area of the base circle x height = pi x (radius)2 x height
Surface Area = (2 x pi x (radius)2 )+ (pi x (diameter) x height)
Q) Let’s try a problem: A cylindrical water tank has a stripe painted around its circumference, as shown in the figure provided. What is the surface area of this stripe?
(1) y = 0.7
(2) The height of the tank is 2 meters.
To find the surface area of the stripe, you need to know the circumference of the cylinder, but there is not data in the question that gives you the radius or diameter to let you find the circumference. Hence the answer should be that neither statement together is sufficient.
About the Author
I am Atul Jose, Founding Consultant of F1GMAT, an MBA admissions consultancy that has worked with applicants since 2009.
For the past 15 years I have edited the application files of admits to the M7 programs: Harvard Business School, Stanford Graduate School of Business, the Wharton School, MIT Sloan, Chicago Booth, Kellogg School of Management, and Columbia Business School, together with admits to Berkeley Haas, Yale School of Management, NYU Stern, Michigan Ross, Duke Fuqua, Darden, Tuck, IMD, London Business School, INSEAD, SDA Bocconi, IESE Business School, HEC Paris, McCombs, and Tepper, plus other programs inside the global top 30.
My work covers the full MBA application deliverable: career planning and profile evaluation, application essay editing, recommendation letter editing, mock interviews and interview preparation, scholarship and fellowship essay editing, and cover letter editing for funding applications. Full bio with credentials and admit history is here.
I am the author of the Winning MBA Essay Guide, the best-selling essay guide covering M7 MBA programs. I have written and updated the guide annually since 2013, which makes the 2026 edition the thirteenth.
The reason I still write and edit essays every cycle: a good MBA essay carries a real applicant's voice. Writing essays for F1GMAT's Books and Editing essays weekly is how I stay calibrated to what current admissions committees respond to.
Contact me for school selection, career planning, essay strategy, narrative development, essay editing, interview preparation, scholarship essay editing, or guidance documents for recommendation letters.