triangles -classroom presentation

Class VKavita Grover

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Elements of a TriangleSidesSide ABSide BCSide CA

Angles ABC ACB BAC

Vertices A,B,C

A

B C

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Types of Triangles

Based on sides

Based on angles

Equilateral

Isosceles

Scalene Acute

Right -angled

Obtuse

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Review ExerciseTick the correct option.1) A triangle is formed by joining

a) 3 points b) 3 collinear pointsc) 3 linesd) 3 non collinear points

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3) How will you denote a side AB of a triangle

a) Line ABb) ABc) ABd) Side AB

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4) The given triangle is

a) Obtuse angle triangle

b) Scalene trianglec) Isosceles triangled) Acute angle

triangle

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Answers

1) b

2) c

3) b

4) d

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Angle sum property of a TriangleThe sum of the angles of a triangle is 180˚.

A

B C

A+ B+ C = 180˚

A

B

C

A+ B+ C= 180˚

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Side property of a TriangleThe sum of the lengths

of any two sides is always greater than the length of the third side .

Side AB= 5cmSide BC= 5cmSide CA= 5 cmAB+BC >CA 5cm+5cm >5cm10 cm>5cm

BC+CA>AB5cm+5cm >5cm10cm>5cm

A

B C11Kavita Grover

Side AB=4.5cmSide BC=7cmSide CA=5cmSide AB+BC>AC4.5cm+7cm>5cm11.5cm>5cm

A

B

C

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