*MAth Formulas* Rectangle Area = length × width Perimeter = 2 (Length + Breadth) Diagonal = √{(length)2 + (width)2} Square Area = (side) ² Perimeter = 4 × side Diagonal = √2 × side Triangle Scalene triangle: If a, b and c are the lengths of the first, second and third sides respectively then (s = semi-parameter) = (a+b+c)/2 And, area = √s(s-a)(s-b)(s-c) right angle triangle If the triangle is right angled, then Area = 1/2 × base × height equilateral triangle If the triangle is equilateral, then Area = {√3/4}(side)² a Radius of incircle of equilateral triangle = a/(2√3) Radius of circumcircle of equilateral triangle with side a = a/√3 Circle *Area = π × (radius)* ² Circumference = 2π × radius Radius = diameter/2 Semicircle Area of ​​semi-circle = 1/2 × π R² *Perimeter of semi-circle* = (π R + 2R) Arc length = 2πRθ/360 Area of ​​sector AOB = 1/2 × (arc AB) × R = 2πR2θ/360 Of the four walls of the room: Area = 2 × height (length + width) Height = Area /{2(Length + Width)} quadrilateral (Quadrilateral) Parallelogram Area = base × height Rhombus Area = 1/2 × product of diagonals Trapezium Area = 1/2 × (sum of parallel sides) × distance between them Trapezoid Area = ½ (DP + BQ) × AC Three dimensional Figures Cuboid If the length, breadth and height of the cuboid are L, B and H respectively then Volume = L × B × H Area of ​​entire surface = 2 (L × B + B × H + H + L) Diagonal = √(L2 + B2 + H2) Cube If each side of the cube is a yes, then Volume = a × a × a = a³ Area of ​​entire surface = 2(a × a + a × a + a × a) = 6a² Diagonal of cube = √(a2 + a2 + a2) = √3 a Cylinder If the radius of the cylinder is r and height or length is h, then Volume = πr²h Area = 2πrh Area of ​​entire surface = (2πrh + 2πr²) Cone If the radius, height of the base of the cone and its slant height are r, h and ℓ respectively, then: Volume = (1/3)πr2h Area of ​​curved surface = πrℓ Area of ​​entire surface = πrℓ + πr² slant height = ℓ = = √(r2 + h2 ) Sphere If the radius of the sphere is r, then Volume = (4/3)πr3 Curved surface area = 4πr² Semisphere Volume = (2/3)πr3 Curved surface area = 2πr² Total surface area = 2πr² + πr² = 3πr² https://whatsapp.com/channel/0029Vb3VMR6J93wYwBLc4H3c/103