##
__AREA__

**I. (i) Area of Rectangle = length ✕ width**

**(ii) Perimeter of Rectangle = 2 ( length + width )**

**II. (i)**

**Area of Square = side**

**✕ side**

**= 1/2**

**✕**

**diagonal**

**✕**

**diagonal**

^{}**(ii) Diagonal of Square = ( √2**

**✕ side )**

**III. Area of the four walls of the room =**

**2 ( length + width )**

**✕ height**

**IV. (i) Area of triangle = 1/2**

**✕**

**base**

**✕ height**

**(ii)**

**Area of triangle = where s = 1/2 (a+b+c) and a,b,c side of triangle.**

**(iii) Area of equilateral triangle =**

**√3/4**

**✕**

**side**

**✕**

**side**

**(iv) The radius of the inner circle of the equilateral triangle with 'a' side =**

**(v) The radius of the circumcircle of equilateral triangle with 'a' side =**

**V. (i) Area of a parallelogram = base**

**✕ height**

**= a**

**✕ h**

**(ii) Area of rhombus = 1/2**

**✕ (Product of diagonals)**

**= 1/2**

**✕ (a**

**✕ b)**

**(iii) Half of the diagonals of a rhombus and one side of the rhombus form a right-angled triangle whose hypotenuse is the side of the quadrilateral.**

**VI. Area of trapezium = 1/2**

**✕ sum of parallel side**

**✕ distance between them**

**= 1/2**

**✕ (a+b)**

**✕ h**

**VII. (i) Area of circle = Ï€R**

^{2}**(ii) Circumference of circle = 2**

**Ï€R**

**(iii) Area of semi-circle = 1/2**

**✕**

**Ï€R**

^{2}**(iv) Perimeter of semi-circle = (**

**Ï€R + 2R)**

**(v) Arc length =**

**(vi) Area of the circle segment AOB = 1/2**

**✕ (arc AB)**

**✕ R =**

## 0 Comments