triangles introduction class 5
TRANSCRIPT
TrianglesClass V
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I can be big or small.You can find me all around.I am made up of three
connected lines.I have three verticesI have three angles
Who am I?
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I am a Triangle
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Parts of Triangle
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Worksheet 1 from DAV Book
to be done.
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Note that
• the unit of measure of an angle is called DEGREE.
Recall
• Angle on a straight line is a straight angle and it
measures 1800 .
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Angle Sum Property of Triangle
Property: Sum of the three angles of a triangle
is always 1800
To be done by activity method in class room
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Worksheet 2 from DAV Book
to be done.
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Side inequality Property of
Triangle
To be done by activity method in class room
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Lets take an example where the sides are
given to be 10 cm, 4 cm and 3 cm. check if it
is possible to make a triangle with given sides
or not.
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Worksheet 3 from DAV Book
to be done.
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Types of Triangle
On the basis of sides On the basis of angles
• Scalene triangle
• Isosceles triangle
• Equilateral triangle
• Acute angled triangle
• Right angled triangle
• Obtuse angled triangle
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Types of Triangle on the
basis of sides
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Scalene Triangle
A triangle in which length of all three sides is
different is called a scalene triangle
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Isosceles Triangle
A triangle in which length of any two sides is same
is called an isosceles triangle
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Equilateral Triangle
A triangle in which length of all three sides is same
is called an equilateral triangle
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Types of Triangle on the
basis of angles
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Acute angled Triangle
A triangle in which all three angles are acute ( <900) is called acute angled triangle.
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Right angled Triangle
A triangle in which one angle is right ( = 900) is called right angled triangle.
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Obtuse angled Triangle
A triangle in which exactly one angle is obtuse ( > 900) is called obtuse angled triangle.
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Worksheet 4 from DAV Book
to be done.
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Thanks!!!
Prepared by: Richa Bhardwaj
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