Proposed Geometry Problem and Solutions.
See complete Problem 184 at:
www.gogeometry.com/problem/p184_triangle_angles_problem.htm
The following solution was received from Ibrahim Elsager.
Post your solutions or ideas in the comments.
Monday, January 26, 2009
Elearn Geometry Problem 184: Triangle, Angles
Labels:
angle,
Problem 184,
solution,
triangle
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<ABD=<ADB=(180-64)/2=58
ReplyDelete<ACB=180-48-58-30=44
<ADC=180-16-x=164-x
Consider Triangle ABC
sin44/AB=sin(58+30)/AC
AB/AC=sin44/sin88=1/2cos44--------(1)
Consider Triangle ADC
sinx/AD=sin(164-x)/AC
AD/AC=sinx/sin(164-x)-------(2)
Since AB=AD, by equating (1) & (2)
1/2cos44=sinx/sin(164-x)
sin(164-x)=2sinxcos44
sin164cosx-cos164sinx=2sinxcos44
sin164cosx=2sinxcos44+cos164sinx
sin164cosx=sinx(2cos44+cos164)
tanx=sin164/(2cos44+cos164)
x=30