Right Prism for SSC Tier-I Exam

The Staff Selection Commission Combined Graduate Level exam is a highly competitive test that opens pathways to prestigious government jobs. Performing well on the Tier-I Quantitative Aptitude section is crucial. Within this, candidates must have a strong grasp of geometry concepts, particularly related to the "Right Prism" syllabus.

This guide will provide an overview of what right prisms are, the key syllabus areas candidates need to focus on, and tips to master this topic for the SSC CGL Tier-I.

Important Details:

Key Syllabus Areas Tips for Mastery
Area and volume calculations Practice visualizing shapes and spatial relationships
Lateral surface area Attempt diverse question types and word problems
Diagonals and space diagonals Build speed through timed practice questions
Frustums and pyramids Learn from SSC CGL previous year papers

What is a Right Prism?

A right prism refers to a three-dimensional geometric solid. It consists of two bases that are polygons, connected by several rectangular faces called lateral faces. These lateral faces meet the base at right angles.

Right prisms can be visualized as stacking multiple identical boxes or layers on top of each other. The height refers to the number of stacked boxes. Common examples include cubes and rectangular cuboids.

Base Shape Prism Name
Triangle Triangular prism
Rectangle Rectangular prism
Square Cube

On the SSC CGL exam, questions on right prisms may provide diagrammatic representations or describe application scenarios where you must visualize the shape and apply formulas correctly.

Key Areas of the "Right Prism" Syllabus

When preparing for questions on right prisms, candidates should focus on mastering the following concepts:

  • Calculating area of base, lateral faces, total surface area and volume
  • Finding lateral surface area using lateral edge length
  • Determining diagonal lengths within the prism
  • Calculating space diagonals connecting opposite corners
  • Relating prisms to pyramids, frustums and other shapes

Area and Volume Calculations

You must remember formulas for area and volume and correctly apply them based on the right prism's dimensions:

Feature Formula
Base area Length x Width
Lateral surface area Perimeter of base x Height
Total surface area Lateral surface area + 2 x Base area
Volume Base area x Height

Lateral Surface Area

The lateral surface area refers to the combined area of all the rectangular lateral faces. It can be calculated in two ways:

1. Using lateral edge length: Add areas of all lateral faces

2. Using perimeter of base & height: Perimeter x Height

You must correctly identify which method to apply based on provided data.

Diagonals and Space Diagonals

Right prism questions may involve calculating:

  • Diagonals of the base
  • Diagonals within lateral faces
  • Space diagonals between opposite corners

Apply Pythagoras theorem and relevant formulas accurately after visualizing the right prism structure.

Strategies for Mastering this Syllabus

Some key tips to master right prisms include:

  • Practice visualizing prisms in 3D to aid better understanding
  • Learn formulas thoroughly and practice direct formula-based questions
  • Attempt more application questions and word problems
  • Solve previous year questions to identify recurring patterns
  • Take timed mocks to improve speed and accuracy

Additionally, refer to trusted textbooks like NCERT for strengthening your fundamentals on geometry concepts related to right prisms.


In the SSC CGL Tier-I exam, right prism questions test your conceptual clarity, visualization, logical reasoning and accuracy in applying formulas. By mastering this syllabus, you will gain overall confidence in tackling the Quantitative Aptitude section.


Q1: How are right prisms and pyramids related?

A1: Right prisms have polygon bases joined by rectangular lateral faces. Pyramids have polygon bases that converge towards a common vertex point. Questions may involve calculating volumes, surface areas etc. of prism-pyramid combinations.

Q2: What is a frustum?

A2: A frustum refers to a prism whose top portion has been sliced off. Questions may require you to calculate volume or surface area of this truncated prism shape.

Q3: How can I master visualizing prisms?

A3: Practice sketching prism diagrams with various base shapes. Observe them from different angles. Construct mini prism models using cardboard. This builds your spatial reasoning ability.

Q4: What are space diagonals in a prism?

A4: Space diagonals connect opposite corners of the prism. You must visualize the 3D structure to determine space diagonal lengths using Pythagoras theorem.

Q5: Where can I find the previous year SSC CGL papers?

A5: You can download PDFs of past SSC CGL papers from the official website or other online resources to aid your preparation.

Q6: Can I crack SSC CGL without coaching?

A6: Yes, with diligence and smart preparation using the right study materials, you can successfully clear the exam without coaching.