MATHS POWER POINT PRESENTATION Class: VIII

UNDERSTANDING QUADRILATERALS.

INTRODUCTION What is a quadrilateral? It is a 4-sided polygon, which is made up entirely of line segments. Quadrilaterals can be divided into 5 types i.e.., square, rectangle, rhombus, trapezium, parallelogram.

WHAT IS A QUADRILATERAL ?

Polygons with 4 sides and 4 angles QUADRILATERALS Polygons with 4 sides and 4 angles 1 4 2 1 1 2 3 1 4 2 4 3 2 4 3 3

TYPES OF QUADRILATERALS Square Parallelogram Rectangle Trapezoid Rhombus Hmmm. They are different shapes, yet they all have 4 sides…

QUADRILATERAL A quadrilateral is a polygon with four sides. A quadrilateral is named by its vertices.

SQUARE It is a quadrilateral having all sides equal. All the angles are 90 degrees. The diagonals are equal and bisect each other perpendicularly. The angle-sum property is 360 degrees.

How are they different? SQUARE 4 congruent sides 4 congruent angles ( Square = opposite of cool.)

RECTANGLE It is a 4-side polygon having opposite sides equal. Diagonals are equal and bisect each other Angle-sum property is 360 degrees. All the angles are 90 degrees.

Trapezium In this polygon, only one pair of opposite sides are equal. Diagonals are unequal

The trapezoid is usually the funkiest looking quadrilateral. How are they different? TRAPEZOID Only 1 pair of parallel sides The trapezoid is usually the funkiest looking quadrilateral.

PARALLELLOGRAM It is a 4-sided polygon having opposites sides of equal length. Diagonals are equal and bisect each other. Angle-sum property is 360 degrees.

How are they different? PARALLELOGRAM 2 pairs of parallel sides Opposite sides congruent Opposite angles congruent

RHOMBUS It is a 4-sided polygon with all side equal. Diagonals are equal and bisect each other perpendicularly. All sides are 90 degrees. Angle-sum property is 360 degrees.

How are they different? RHOMBUS A parallelogram with 4 congruent (equal) sides

A N C B Q R D E M O P S G F P In figure A, the quadrilateral is named PQRS or QRSP or RSPQ or SPQR. The order of the vertices is important. In figure B, the quadrilateral is named MNOP. In figure C, the quadrilateral is named DEFG.

B A C D In quadrilateral ABCD, the vertices are A, B,C, and D. Vertices A and B, B and C, C and D, D and A are consecutives vertices. Vertices A and C, B and D are opposite vertices. D

B A C D Two sides with common vertex, like AB and BC, are consecutive sides. AB and DC, AD and BC, on the other hand are opposite hand.

B A C D Two angles with a common side, like <A and <D, are consecutive angles. <A and <C, <B and <D on the other hand are opposite angles.

B A C D Segments joining opposite vertices like AC and BD are called diagonals of the quadrilateral.

Convex quadrilateral QRST, QS and RT intersect. M T Q O N S P R Convex quadrilateral QRST, QS and RT intersect. Nonconvex quadrilateral MNOP, MO and NP do not intersect.

Now YOU try it Draw a square. Draw a rectangle. Draw a trapezoid. Draw a parallelogram Draw a rhombus. **EXTRA CREDIT: DON”T label your drawings. Switch with a friend and have them label your quadrilaterals and you label theirs.

CONCLUSION Learning Outcome: By seeing this project, we can understand the all aspects/info about quadrilaterals. Identify the quadrilaterals properly and their properties i.e., angle-sum, exterior-angle property etc.

BIBLIOGRAPHY We have taken help from the following sources to make this project a grand success: VIII Class Maths Textbook Google search Wikipedia Search on Quadrilaterals www.author stream.com – Downloaded PPT.

THE END THANK YOU.