circumcentre, incentre and orthocentre of a triangle

1. Activity 6
Objective: To find
Incentre,
Circumcentre and
Orthocentre by paper
folding.
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Material required:
3 cut outs of triangles of
any type, fevicol, pair of
scissors, glue, sketch
pen, ruler etc...

3. Recall
An angle bisector is a ray that
cuts an angle in half.
Incentre: Where a triangle’s
three angle bisectors intersects;
the incentre is the centre of a
circle inscribed inside the
triangle.
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4. Incentre
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5. A perpendicular bisector is a line that
forms a 900 angle with a segment and
cuts the segment in half.
Circumcentre: Where three
perpendicular bisectors of the sides of
a triangle intersect; the circumcentre is
the centre of a circle circumscribed
about the triangle.
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6. Circumcentre
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7. The altitude of a triangle is a segment
from a vertex of the triangle to the
opposite side (or to the extension of
opposite side if necessary). That
opposite side is called as base.
Orthocentre: where the triangle’s
three altitudes intersects.
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8. Orthocentre
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9. Orthocentre in different type of triangles
Acute angled triangle Obtuse angled triangle Right angled triangle
(Inside triangle) (outside triangle) (on the side of triangle)
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Thank you
Richa Bhardwaj