Area Of Plane Figures G

AREA OF PLANE FIGURES A figure lying in a plane is called a plane figure. A plane figure made up of lines or curves or both. A part of the plane enclosed by a simple closed figure is called a plane region. The magnitude of a plane region is called its area. Square, rectangle, trapezium, rhombus, circle all are plane figures. There is brief description of these figures: 1. Square: Any parallelogram with all sides equal and every angle is right angle is called a square. Area of a square = Side* Side In figure AB=BC=CD=AD=side D

A

C

B

2. Rectangle: A rectangle is a parallelogram, one of whose angle is right angle and parallel sides are equal. Area of rectangle =length*breadth In figure AB=DC= length, AD=BC= breadth D

A

C

B

3. Trapezium: A quadrilateral in which one pair of opposite sides are parallel is called trapezium. Area of a trapezium: 1/2 * h * (b1+b2) Area of a trapezium=Area of Triangle ABC + Area of triangle ACD =1/2 * AB * CL +1/2 * DC * AM =1/2 * b1 * h+1/2 * b2 * h =1/2 * h * (b1+b2) M

D

b2

C

h

A

h

L

b1

B

4. Rhombus: A parallelogram in which all sides are equal is called a rhombus.

D

Area of rhombus = Base * Altitude = AB * H

C

h

A

B

5. Circle : The magnitude of the region enclosed by a circle is area of circle. If r is radius of the circle then area of the circle = ∏ * r2

r O

Govt. Girls. Sen. Sec. School, Hargobindpur (Ludhiana) Name of Students 1. 2. 3. 4. 5.

Harinder Kaur Ramandeep Kaur Navjot Kaur Rajvir Kaur Savreet Kaur

Bibliography 1. Text Book Of 7th Class