Mensuration: All Formulas with Diagrams for SSC & Railway Exams

Mensuration carries 3-5 questions in SSC CGL. Memorize these formulas and you'll never miss a mensuration question.

2D Shapes

Rectangle: Area = l×b, Perimeter = 2(l+b), Diagonal = √(l²+b²). Circle: Area = πr², Circumference = 2πr. Triangle: Area = ½×base×height. Equilateral: Area = (√3/4)a². Trapezium: Area = ½×(sum of parallel sides)×height.

3D Shapes

Cube: Volume = a³, TSA = 6a², Diagonal = a√3. Cylinder: Volume = πr²h, CSA = 2πrh, TSA = 2πr(r+h). Cone: Volume = (1/3)πr²h, Slant height = √(r²+h²). Sphere: Volume = (4/3)πr³, SA = 4πr².

Common Question Types

Type 1: Find area/volume given dimensions. Type 2: Find dimension given area/volume. Type 3: Conversion problems (melting a sphere to form cones). Type 4: Combined shapes (hemisphere on cylinder).