document.write( "Question 1151811: A= 25 degrees
\n" ); document.write( "a=5
\n" ); document.write( "b=11\r
\n" ); document.write( "\n" ); document.write( "Solve the triangle ABC\r
\n" ); document.write( "\n" ); document.write( "Thank you!!
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Algebra.Com's Answer #773670 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!

\n" ); document.write( "Angles
\n" ); document.write( "A = 25
\n" ); document.write( "B = unknown
\n" ); document.write( "C = unknown\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Sides
\n" ); document.write( "a = 5
\n" ); document.write( "b = 11
\n" ); document.write( "c = unknown\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "We have two known sides an angle that is not between the two sides. This is the SSA case which has 3 possibilities
  • Zero triangles are possible
  • Exactly one triangle is possible
  • Exactly two triangles are possible
The SSA case leads to ambiguity.\r
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\n" ); document.write( "\n" ); document.write( "Use the law of sines to solve for angle B
\n" ); document.write( "sin(A)/a = sin(B)/b
\n" ); document.write( "sin(25)/5 = sin(B)/11
\n" ); document.write( "0.0845236523481399 = sin(B)/11
\n" ); document.write( "11*0.0845236523481399 = 11*sin(B)/11
\n" ); document.write( "0.929760175829539 = sin(B)
\n" ); document.write( "sin(B) = 0.929760175829539
\n" ); document.write( "arcsin(sin(B)) = arcsin(0.929760175829539)
\n" ); document.write( "B = arcsin(0.929760175829539) or B = 180 - arcsin(0.929760175829539)
\n" ); document.write( "B = 68.3974616057519 or B = 111.602538394248
\n" ); document.write( "B = 68.397 or B = 111.603\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "If B = 68.397, then C = 180-A-B = 180-25-68.397 = 86.603
\n" ); document.write( "If B = 111.603, then C = 180-A-B = 180-25-111.603 = 43.397
\n" ); document.write( "In either case, the value of B produces a positive C value. Therefore, we have two sets of solutions to represent the two possible triangles.\r
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\n" ); document.write( "\n" ); document.write( "With this info: C = 86.603, a = 5, b = 11, we can find the unknown side c using the law of cosines
\n" ); document.write( "c^2 = a^2 + b^2 - 2*a*b*cos(C)
\n" ); document.write( "c^2 = (5)^2 + (11)^2 - 2*(5)*(11)*cos(86.603)
\n" ); document.write( "c^2 = 25 + 121 - 110*0.0592541057795245
\n" ); document.write( "c^2 = 25 + 121 - 6.51795163574769
\n" ); document.write( "c^2 = 139.482048364252
\n" ); document.write( "c = sqrt(139.482048364252)
\n" ); document.write( "c = 11.8102518332274
\n" ); document.write( "c = 11.810\r
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\n" ); document.write( "\n" ); document.write( "So one solution consists of
\n" ); document.write( "Angles
\n" ); document.write( "A = 25
\n" ); document.write( "B = 68.397
\n" ); document.write( "C = 86.603
\n" ); document.write( "Sides
\n" ); document.write( "a = 5
\n" ); document.write( "b = 11
\n" ); document.write( "c = 11.810\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "--------------------------------------------------\r
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\n" ); document.write( "\n" ); document.write( "Use the law of cosines again, but now with C = 43.397
\n" ); document.write( "The values of 'a' and b stay the same
\n" ); document.write( "c^2 = a^2 + b^2 - 2*a*b*cos(C)
\n" ); document.write( "c^2 = (5)^2 + (11)^2 - 2*(5)*(11)*cos(43.397)
\n" ); document.write( "c^2 = 25 + 121 - 110*0.726610645792925
\n" ); document.write( "c^2 = 25 + 121 - 79.9271710372218
\n" ); document.write( "c^2 = 66.0728289627782
\n" ); document.write( "c = sqrt(66.0728289627782)
\n" ); document.write( "c = 8.12851948160169
\n" ); document.write( "c = 8.129\r
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\n" ); document.write( "\n" ); document.write( "The other solution consists of
\n" ); document.write( "Angles
\n" ); document.write( "A = 25
\n" ); document.write( "B = 111.603
\n" ); document.write( "C = 43.397
\n" ); document.write( "Sides
\n" ); document.write( "a = 5
\n" ); document.write( "b = 11
\n" ); document.write( "c = 8.129\r
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\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "--------------------------------------------------\r
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\n" ); document.write( "\n" ); document.write( "In summary, the two possible triangles are
\n" ); document.write( "\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "\r\n" ); document.write( "\n" ); document.write( "
Triangle #1Triangle #2
Angles
\n" ); document.write( "A = 25
\n" ); document.write( "B = 68.397
\n" ); document.write( "C = 86.603
Sides
\n" ); document.write( "a = 5
\n" ); document.write( "b = 11
\n" ); document.write( "c = 11.810
Angles
\n" ); document.write( "A = 25
\n" ); document.write( "B = 111.603
\n" ); document.write( "C = 43.397
Sides
\n" ); document.write( "a = 5
\n" ); document.write( "b = 11
\n" ); document.write( "c = 8.129
\r
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\n" ); document.write( "\n" ); document.write( "Diagram
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\n" ); document.write( "The decimal values are approximate to three decimal places.
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