Two corners of a triangle have angles of (5 pi )/ 12 5π12 and ( pi ) / 12 π12. If one side of the triangle has a length of 16 16, what is the longest possible perimeter of the triangle?

1 Answer
Feb 27, 2018

Longest possible perimeter

P = a + b + c = color (blue)(137.532)P=a+b+c=137.532 units

Explanation:

A = (5pi)/13, B = pi / 12, C = pi - pi/12 - (5pi)/12 = pi/2A=5π13,B=π12,C=ππ125π12=π2

To get the longest perimeter, length 16 should correspond to hat B= (pi/12)ˆB=(π12)

Applying law of sines,

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a = (b * sin A) / sin B = (16 * sin ((5pi)/12)) / sin (pi/12) = 59.7128a=bsinAsinB=16sin(5π12)sin(π12)=59.7128

c = sqrt(a^2 + b^2) = sqrt(16^2 + 59.7128^2) = 61.8192c=a2+b2=162+59.71282=61.8192

Longest possible perimeter

P = a + b + c = 16 + 59.7128 + 61.8192 = color (blue)(137.532)P=a+b+c=16+59.7128+61.8192=137.532