1. Area of rectangle (A) = length(l) * Breath(b)
2. Perimeter of a rectangle (P) = 2 * (Length(l) + Breath(b))
3. Area of a square (A) = Length (l) * Length (l)
4. Perimeter of a square (P) = 4 * Length (l)
5. Area of a parallelogram(A) = Length(l) * Height(h)
6. Perimeter of a parallelogram (P) = 2 * (length(l) + Breadth(b))
7. Area of a triangle (A) = (Base(b) * Height(b)) / 2
And for a triangle with sides measuring “a” , “b” and “c” , Perimeter = a+b+c
and s = semi perimeter = perimeter / 2 = (a+b+c)/2
And also . Area of triangle
This formulas is also knows as “Heroe’s formula”.
8. Area of triangle(A) =
Where , A , B and C are the vertex and angle A , B , C are respective angles of triangles and a , b , c are the respective opposite sides of the angles as shown in figure below:
area of triangle - mensuration
9. Area of isosceles triangle =
Where , a = length of two equal side , b= length of base of isosceles triangle.
10. Area of trapezium (A) =
Where , “a” and “b” are the length of parallel sides.
11. Perimeter of a trapezium (P) = sum of all sides
12. Area f rhombus (A) = Product of diagonals / 2
13. Perimeter of a rhombus (P) = 4 * l
where l = length of a side
14. Area of quadrilateral (A) = 1/2 * Diagonal * (Sum of offsets)
15. Area of a Kite (A) = 1/2 * product of it’s diagonals
16. Perimeter of a Kite (A) = 2 * Sum on non-adjacent sides
17. Area of a Circle (A) =
Where , r= radius of the circle and d= diameter of the circle.
18. Circumference of a Circle =
r= radius of circle
d= diameter of circle
19. Total surface area of cuboid =
where , l= length , b=breadth , h=height
20. Total surface area of cuboid =
where , l= length
21. length of diagonal of cuboid =
22. length of diagonal of cube = 
23. Volume of cuboid = l * b * h
24. Volume of cube = l * l* l
25. Area of base of a cone = 
26. Curved surface area of a cone = C
Where , r = radius of base , l = slanting height of cone
27. Total surface area of a cone = 
28. Volume of right circular cone = 
Where , r = radius of base of cone , h= height of the cone (perpendicular to base)
29. Surface area of triangular prism = (P * height) + (2 * area of triangle)
Where , p = perimeter of base
30. Surface area of polygonal prism = (Perimeter of base * height ) + (Area of polygonal base * 2)
31. Lateral surface area of prism = Perimeter of base * height
32. Volume of Triangular prism = Area of the triangular base * height
33. Curved surface area of a cylinder = 
Where , r = radius of base , h = height of cylinder
34. Total surface area of a cylinder = 
35. Volume of a cylinder = 
36. Surface area of sphere = 
where , r= radius of sphere , d= diameter of sphere
37. Volume of a sphere = 
38. Volume of hollow cylinder = 
where , R = radius of cylinder , r= radius of hollow , h = height of cylinder
39. Surface area of a right square pyramid = 
Where , a = length of base , b= length of equal side ; of the isosceles triangle forming the slanting face.
40. Volume of a right square pyramid = 
41. Area of a regular hexagon = 
42. area of equilateral triangle = 
43. Curved surface area of a Frustums = 
44. Total surface area of a Frustums = 
45. Curved surface area of a Hemisphere = 
46. Total surface area of a Hemisphere = 
47. Volume of a Hemisphere = 
48. Area of sector of a circle = 
where , 
= measure of angle of the sector , r= radius of the sector
= measure of angle of the sector , r= radius of the sector