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Indonesia Regional MO OSP SMA - geometry
2012.4
2012.4
Part of
Indonesia Regional MO OSP SMA - geometry
Problems
(1)
AB + AC > = BC cos (<BAC) + 2AH sin(<BAC) , where AH altitude
Source: 2012 Indonesia MO Province P2 q4 OSP
12/10/2020
Given an acute triangle
A
B
C
ABC
A
BC
. Point
H
H
H
denotes the foot of the altitude drawn from
A
A
A
. Prove that
A
B
+
A
C
≥
B
C
c
o
s
∠
B
A
C
+
2
A
H
s
i
n
∠
B
A
C
AB + AC \ge BC cos \angle BAC + 2AH sin \angle BAC
A
B
+
A
C
≥
BC
cos
∠
B
A
C
+
2
A
Hs
in
∠
B
A
C
geometry
geometric inequality
Geometric Inequalities
Trigonometric inequality
trigonometry