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Given angles
MATHEMATICS · Subjective · CBSE · Mathematics · Triangles · Triangles
Problem
Given angles,
A
,
B
A, B
A
,
B
and
C
C
C
of
Δ
A
B
C
\Delta ABC
Δ
A
B
C
. Let
M
M
M
be the mid-point of segment
A
B
AB
A
B
and let
D
D
D
be the foot of the bisector of
∠
C
\angle C
∠
C
. Find the ratio of
Area of
Δ
C
D
M
Area of
Δ
A
B
C
\frac{\text{Area of } \Delta CDM}{\text{Area of } \Delta ABC}
Area of
Δ
A
B
C
Area of
Δ
C
D
M
and also
cos
ϕ
=
cos
∠
D
C
M
\cos \phi = \cos \angle DCM
cos
ϕ
=
cos
∠
D
C
M
.
Related theory
Trigonometric Identities
Trigonometric Functions
Basic Proportionality Theorem
Similarity
Basic Proportionality Theorem (BPT)
Triangles
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