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Mathematics
Mathematics
Problem
a. In
△
A
B
C
\triangle ABC
△
A
B
C
,
∠
A
=
2
y
∘
\angle A = 2y^{\circ}
∠
A
=
2
y
∘
,
∠
B
=
y
+
20
∘
\angle B = y + 20^{\circ}
∠
B
=
y
+
2
0
∘
and
∠
C
=
40
∘
\angle C = 40^{\circ}
∠
C
=
4
0
∘
.
△
D
E
F
\triangle DEF
△
D
E
F
is congruent to
△
A
B
C
\triangle ABC
△
A
B
C
in the given order. Find
y
y
y
. b. If the side corresponding to
D
E
DE
D
E
in
△
A
B
C
\triangle ABC
△
A
B
C
is
A
B
=
23
cm
AB = 23\,\text{cm}
A
B
=
23
cm
and
D
E
=
3
x
+
2
cm
DE = 3x + 2\,\text{cm}
D
E
=
3
x
+
2
cm
, find
x
x
x
. c. Determine
∠
E
F
D
\angle EFD
∠
E
F
D
.
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