NCERT Class 9 Maths Formula CBSE Board Sample Problems Part 11 (For CBSE, ICSE, IAS, NET, NRA 2022)

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11. Heron Formula

Heron Formula
S. no	Term	Description
1	Mensuration	It is branch of mathematics which is concerned about the measurement of length, area, and Volume of plane and Solid figure
2	Perimeter	(a) The perimeter of plane figure is defined as the length of the boundary (b) Its units are same as that of length i.e.. . , m, cm, km
3	Area	(a) The area of the plane figure is the surface enclosed by its boundary (b) Its unit is square of length unit. i.e.. . ,

Unit Conversion

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

Perimeter and Area of Different Figure
N	Shape	Perimeter/height	Area
1	Right angle triangle Base = b, Height = h Hypotenuse = d	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 breadth L and B respectively		A = LX B
6	Parallelograms Two sides are given as a and b		A = Base X height When the diagonal is also given, say d Then W here
7	Rhombus Diagonal d₁ and d₂ are given
8	Quadrilateral (a) All the sides are given a, b, c, d (b) Both the diagonal are perpendicular to each other (c) When a diagonal and perpendicular to diagonal are given where d is diagonal and and are perpendicular to that	(a)	(a) Where (b) Where and are the diagonal (c)