class 8 math lesson 10 (geometry)
TRANSCRIPT
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1
1
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10
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c
db
a
DA
EB
F
x
C
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...
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, :() () () () ()
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a
b
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EB Cax x
b
A
F
D
: , a b x
b
a
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:(1) BE BC=a B BF
BA=b (2) AC a b
D () A, D C,D , ABCD-
xEBF
ABC
EB Cax
b
A
F
D
b
a
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-.(Extra-)
1 4 . .3 . . .() () ()
60
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5 . .4 . . 65
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1. ?
. 7 . . 6 . . ?
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-:
1 4 . .3 . . .() () ()
60