Mensuration All important formulas

Mensuration Formulas For 2D Shapes

Shape	Area (Square units)	Perimeter (units)	Figure
Square	a2	4a
Rectangle	l × b	2 ( l + b)
Circle	πr2	2 π r
Scalene Triangle	√[s(s−a)(s−b)(s−c)], Where, s = (a+b+c)/2	a+b+c
Isosceles Triangle	½ × b × h	2a + b
Equilateral Triangle	(√3/4) × a2	3a
Right Angle Triangle	½ × b × h	b + hypotenuse + h
Rhombus	½ × d1 × d2	4 × side
Parallelogram	b × h	2(l+b)
Trapezium	½ h(a+b)	a+b+c+d

Mensuration Formulas for 3D Shapes

Shape	Volume (Cubic units)	Curved Surface Area (CSA) or Lateral Surface Area (LSA) (Square units)	Total Surface Area (TSA) (Square units)	Figure
Cube	a3	–	6 a2
Cuboid	l × w × h	–	2 (lb +bh +hl)
Sphere	(4/3) π r3	4 π r2	4 π r2
Hemisphere	(⅔) π r3	2 π r 2	3 π r 2
Cylinder	π r 2 h	2π r h	2πrh + 2πr2
Cone	(⅓) π r2 h	π r l	πr (r + l)

Mensuration Problems

Question: Find the area and perimeter of a square whose side is 5 cm?

Solution:

Given:

Side = 5 cm

Area of a square = a2 square units

Substitute the value of “a” in the formula, we get

Area of a square = 52
A = 5 x 5 = 25

Therefore, the area of a square = 25 cm2

The perimeter of a square = 4a units

P = 4 x 5 =20

Therefore, the perimeter of a square = 20 cm.