Mensuration Formulas for 3D Figures
8. Mensuration Formulas for CUBOID
In the following formulae, l = length, b = breadth and h = height
Total surface area of cuboid = 2 (lb + bh + lh)
Length of diagonal of cuboid= √(l2+b2+h2)
Volume of cuboid = l × b × h
9. Mensuration Formulas for CUBE
In the following formulae, a = side of a cube
Volume of cube = a3
Total surface area of cube = 6a2
Length of Leading Diagonal of Cube = a√3
10. Mensuration Formulas for CONE
In the following formulae, r = radius of base, l = slant height of cone and h = height of the cone (perpendicular to base)
Slant height of a cone = l =√(h2+r2 )
Curved surface area of a cone = C = π × r × l
Total surface area of a cone = π × r × (r + l)
Volume of right circular cone =1/3 πr2h
11. Mensuration Formulas for CYLINDER
In the following formulae, r = radius of base, h = height of cylinder
Curved surface area of a cylinder = 2πrh
Total surface area of a cylinder = 2πr(r + h)
Volume of a cylinder = πr2h
12. Mensuration Formulas for SPHERE
In the following formulae, r = radius of sphere, d = diameter of sphere
Surface area of a sphere = 4πr2 = πd2
Volume of a sphere = (4/3) πr3 = (1/6)πd3
13. Mensuration Formulas for HEMISPHERE
In the following formulae, r = radius of sphere
Volume of a hemisphere =(2/3)πr3
Curved surface area of a hemisphere = 2πr2
Total surface area of a hemisphere = 3πr2
14. Mensuration Formulas for HOLLOW CYLINDER
Hollow cylinder made by cutting a smaller cylinder of same height and orientation out of a bigger cylinder.
Volume of hollow cylinder = πh(R2– r2)
(Where, R = radius of cylinder, r = radius of cavity, h = height of cylinder)
(Where, R = radius of cylinder, r = radius of cavity, h = height of cylinder)
15. Mensuration Formulas for FRUSTUM OF A RIGHT CIRCULAR CONE
Frustum is created when a plane cuts a cone parallel to its base.
In the following formulae, R = radius of the base of the frustum, r = radius of the top of the frustum,
h = height of the frustum, l = slant height of the frustum
In the following formulae, R = radius of the base of the frustum, r = radius of the top of the frustum,
h = height of the frustum, l = slant height of the frustum
If a cone is cut by a plane parallel to the base of the cone, the lower part is called the frustum of the cone.
Slant height of the frustum =l=√(h2+(R-r)2)
Curved surface area of frustum = π(R + r)l
Total surface area of frustum = π(R + r)l + π(R2 + r2)
Volume of the frustum=(1/3)πh(R2+r2+Rr)
16. Mensuration Formulas for PRISM
Prism consists of two polygonal bases which are parallel to each other.
These bases are joined by lateral faces, which are perpendicular to the polygonal bases.
The number of lateral faces is equal to the number of sides in the polygonal base. Thus, the base of a prism could be of various shapes, namely, triangular, quadrangular, pentagonal etc.
Volume of prism = Base area × height
Lateral surface area of prism = perimeter of base × height
Total surface area of prism = Lateral surface area + (2 × base area)
17. Mensuration Formula for PYRAMID
Pyramid consists of a polygonal base and triangles at its sides. These triangles are called faces.
The base could be of any shape, whereas the faces are generally isosceles triangles.
All these triangular faces meet in a single point called the apex.
Total surface area of pyramid = base area + (number of sides × ½ × slant height × base length)
Volume of pyramid = (1/3) × base area × height
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