# NCERT Class 9 MathematicsHerons Formula (Mensuration) Board Sample Problems (For CBSE, ICSE, IAS, NET, NRA 2022)

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Mensuration

It is branch of mathematics which is concerned about the measurement of length, area and Volume of plane and Solid figure

Perimeter

The perimeter of plane figure is defined as the length of the boundary

It units is same as that of length i.e.. m, cm, km

 1 Meter 10 Decimeter 100 centimeter 1 Decimeter 10 centimeter 100 millimeter 1 Km 10 Hectometer 100 Decameter 1 Decameter 10 meter 1000 centimeter

Area

The area of the plane figure is the surface enclosed by its boundary

It unit is square of length unit. i.e..

 1 square Meter 100 square Decimeter 10000 square centimeter 1 square Decimeter 100 square centimeter 10000 square millimeter 1 Hectare 100 square Decameter 10000 square meter 1 square myraimeter 100 square kilometer square meter

Perimeter and Area of different figure

 N Shape Perimeter/height Area 1 Right angle triangle Base = b, Height = h Hypotenuse = d P Height = h 2 Isosceles right angled triangle Equal side = a Height = a 3 Any triangle of sides a , b, c Where This is called Heron՚s formula (sometimes called Hero՚s formula) is named after Hero of Alexandria 4 Square Side = a 5 Rectangle of Length and breath L and B respectively 6 Parallelograms Two sides are given as a and b When the diagonal is also given, say dThenWhere 7 Rhombus Diagonal and are given 8 Quadrilateral(a) All the sides are(b) Both the diagonal are perpendicular to each other(c) When a diagonal and perpendicular to diagonal are given (a) P (a) Where (b) where and are the diagonal(c) where d is diagonal and and are perpendicular to that