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Quadrila terals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course
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Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Dec 27, 2015

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Page 1: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Quadrilaterals

Presented By :-

PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh

2nd spell inservice course

Page 2: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

LEARNING Objective's

• Definition of Quadrilateral.• Types of Quadrilateral.• Difference between

Rhombus & Square and Trapezoid &Parallelogram.

• Angle sum property of Quadrilateral.

Page 3: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Game between three players

Page 4: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

One player join them

Page 5: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Definition:-

“A Quadrilateral is polygon with four sides. And A polygon is a closed shape consisting of line segments that has at least three sides. “

OR

“A flat closed shape with four straight sides is called Quadrilaterals“

•A quadrilaterals has four sides, four angles and four vertices.

Page 6: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

“Quad” means four. Why would all of these shapes be called “quadrilaterals”?

Each shape has four sides.

Quadrilaterals

Page 7: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Square• A square has four sides that are each

the same length. • It also has four right angles (perfect

corners).

1

2 3

4

Page 8: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Rhombus• A rhombus has four sides

that are each the same length.

• But it has two acute and two obtuse angles.

acute

acuteobtuse

obtuse

Page 9: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Square and Rhombus

• A square and a rhombus both have four sides that are the same length. So, how are they different?

Page 10: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Square and Rhombus• A rhombus can be thought

of as a slanted square.• If we push on the left-hand

side of this square, it might end up looking like…

a rhombus.

Page 11: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

The only difference between a square and a rhombus is their angles.

Page 12: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Trapezoid• A trapezoid has four sides. • Two sides are parallel. • The opposing two sides are

not parallel.

Those are parallel.

Those are not parallel.

Page 13: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Rectangle•A rectangle has four sides – two long sides and two short sides.

•Two sides are parallel.

•The opposing two sides are also parallel.

•It also has four right angles.

Page 14: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Parallelogram•A parallelogram has four sides – two long sides and two short sides.

•Opposite sides are parallel.

•But, it has two acute and two obtuse angles.

Page 15: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Rectangle and Parallelogram• A parallelogram can be

thought of as a slanted rectangle.

• If we push on the left-hand side of this rectangle, it might end up looking like… a parallelogram.

Page 16: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

The only difference between a rectangle and a parallelogram is their angles.

Page 17: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

COMPARISION OF QUADRILATERALS.

Square All sides are equal & parallel

Each angle 90°

Rhombus All sides are equal & parallel

2 angles acute & 2 obtuse.

Trapezoid One pair of opposite sides is parallel

2 angles acute & 2 obtuse

Parallelogram Both pair of opposite sides is parallel

2 angles acute & 2 obtuse

Page 18: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

RHOMBUS

RECTANGLE

SQUARE

Page 19: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Angle sum Property of a Quadrilateral• Let ABCD be a quadrilateral and A & C joined to get

diagonal AC. We obtain two triangles ∆ ADC & ∆ ABCUsing Angle sum property in ∆ADC DAC + ACD + D = 180° ----------------- (1)

Similarly, in ∆ ABC

CAB + ACB + A = 180° ---------------- (2)

Adding (1) and (2) we get

DAC + ACD+ D + CAB + ACB + B = 180° + 180°

Also, DAC + CAB = A and ACD + ACB = C

SO A + B + C + D =360°

The sum of the angles of a quadrilateral is 360°

Page 20: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Sample problem• The angles of quadrilateral are in the ratio

3:5:9:13.Find all the angles of the quadrilateral.• Sol‘n:-Let the angles are 3k,5k,9k&13 (multiple of

k) We know Sum of angles is equal to 360° . So 3k+5k+9k+13k = 360° Or 30k = 360° Or k= 360° /30 Or k=12 Thus angle of quadrilateral are 36°,60°,108 ° & 156.°

Page 21: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.

Evaluation

• Quadrilateral whose two opposite sides are parallel is called ………….

• Trapezoid has ……. Pair of parallel sides.

• Polygon has ………or more sides.• The sum of angles in a quadrilateral is

……• If the angles of parallelogram is in ratio

1:2:1:2. Find the angles‽

Page 22: Quadrilaterals Presented By :- PAWAN SINGH T.G.T(Maths) K.V. NO.2 AFS Suratgarh 2 nd spell inservice course.