In triangle ABC above, what is the length of side BC?
1) Line segment AD has length 6.
2) x = 36
A 1
B 2
C T
D E
E N
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Length of a triangle
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Morgoth
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Question BC=?
AD = BC, let angle ABD = y
x+y = 2x [external triangle theorem]
y = 2x-x = x
y=x
if y=x, then AD=BD.
AD= BD and BC=BD, therefore AD=BC
Statement I
AD=6, therefore BC=6
Sufficient.
Statement II
x=36, we cannot find the side just by knowing the angle.
Insufficient.
Hence A.
Hope this helps.
AD = BC, let angle ABD = y
x+y = 2x [external triangle theorem]
y = 2x-x = x
y=x
if y=x, then AD=BD.
AD= BD and BC=BD, therefore AD=BC
Statement I
AD=6, therefore BC=6
Sufficient.
Statement II
x=36, we cannot find the side just by knowing the angle.
Insufficient.
Hence A.
Hope this helps.
