# Geometry Formulas, Area and Volumes, Cube, Cuboid, Cylinder, Hemisphere, Cone, Sphere,Frustum, Online Help

Area of some rectilinear figures

• Area of a Triangle : 1/2 x Base x Heights
• Area of Equilateral Triangle : Sqrt(3)/4 x (Side)2
• Area of a Triangle – Hero’s formula :
• Sqrt{s (s – a) (s – b) (s – c)} where 2s = a + b + c.
• Area of Rectangle = Length x Breadth
• Area of a Square = (Side)2
• Area of Four Walls = 2 x height (Length + breadth)
• Area of Rhombus = 1/2 x (Products of Diagonals)
• Area of Trapezium = 1/2 x (Sum of Parallel Sides) x (Distance between Parallel lines)
• Area of Parallelogram = Base x Altitude
• Somestandards units of Area
• 100mm2 = 1 cm2, 100 cm2, = 1 dm2
• 100dm2 = 1 m2, 100 m2, = 1 are
• 100arcs = 1 hactare
• 100 hactare = 1 km2

Area related to Circles:

 Circumference of a Circle or Perimeter of a Circle: The Distance arround the circle or the length of a circle is called its circumference or perimeter. Circumference (Perimeter) of a circle = d or 2r, where, r is the radius of the circle and = 22/7 Circle: If r be the radius of a circle, and its center is O. Area of a Circle = r2 Area of a Semi-Circle = r2 Area of a Quadrant = r2 Perimeter of a Semi Circle: If r be the radius of a circle, and its center is O. Perimeter of a Semi Circle : r + 2r Area of a Ring: If r be the radius of a circle, and its center is O. Area of a ring or Annulus : (R2 – r2) Length of arc: Length of arc AB = or Area and Perimeter of a Sector : Area of a Sector OACBO = or (l x r) Area of a Sector OACBO = Length of arc AB + 2r Area of a Segment : Area of a Minor Segemnt ACBA : Area of a sector OACBO – Area of Triangle OAB = – r2sin(theta) Area of a Major Segment BDAB : Area of a circle – Area of a minor segment ACBA =r2 – Area of minor segment ACBA

Surface Area and Volumes: