SSC CGL 2020 Exam Topic - Quantitive Abilities

SSC Preparation Strategies & S Published on 15 February 2020

Quantitative Abilities

The SSC has notified SSC CGL new vacancy 2020 through its website.

The candidates need to practice hard to score well in the exam.


Regular Polygons


  • Regular polygons are the geometrical structures where all the sides and angles of the structure are equal. 
  • It includes triangle (Regular polygon with 3 sides), quadrilateral (Regular Polygon with 4 sides), Pentagons (Regular Polygon with 5 sides), etc. 
  • These are also called as an n-sided polygon, where n is the number of sides in a polygon.

For example, a triangle is a 3- sided polygon with n = 3.

  • There may be to types of regular polygons and these two are star and convex. 

Basic properties of Regular Polygons are as follows:


  1. Symmetry: These types of regular polygons have a symmetrical reflection.
  2. The sum of each interior and exterior angle at a single vertex is always 1800.
  3. The exterior angle of regular polygon must be 3600/n, where n is the side of a regular polygon.
  4. Number of diagonals in a regular polygon can be calculated from the formula 12*n* (n-3) where n is the side of a regular polygon. For example,

In a square where n=4,

The number of diagonals are = 12* 4* (4-3)

                                              = 12*4*1

                                              = 2

                                                    

Right Prism (SSC CGL 2020 Exam)


  • Right Prism is the solid geometrical structure bounded by polygon at its base and parallelograms at the other two sides and sides are perpendicular (900) to the ends.


  • It is a 3- dimensional structure.
  • On the basis of different polygons the name of right prism changes.

For example, when the base polygon is a triangle, it is called the right triangle prism or when the base polygon is rectangular it is called right rectangular prism and so on.


Formulas related to Right Prism are as follows:


  1. Volume of a Right Prism= Area of Base Polygon * Height of the right prism 
  2. Surface area of a Right Prism= (2 * Area of base Polygon) + surface area of parallelograms

  

Right Circular Cone (SSC CGL 2020 Exam)


  • The right circular cone is a geometrical structure of a cone that has a circular section and its axis is perpendicular (900) to the base of the cone.
  • It is a cone with a circular base.

          

  • The right circular cone also has slant height as a measurement denoted by l which joins the vertex of the cone to the exterior point of the circular base of a right circular cone.
  • All measured elements in a right circular cone are equal.
  • A triangle formed from the vertex to the base of the right circular cone always forms an isosceles triangle. 

Formulas related to Right Circular Cone are as follows:


  1. Slant height of Right Circular Cone

Slant height l=h2+r2

2. Lateral Surface Area of Right Circular Cone

    Lateral Surface Area = πrl

3. Total Surface Area of a Right Circular Cone

Total Surface Area = π (r+ l) r

4. Volume of Right Circular Cone:

Volume = 13πr2h



All the best to all the aspirants of SSC-CGL2020!