Two corners of a triangle have angles of (5 pi ) / 12 and (3 pi ) / 8 . If one side of the triangle has a length of 8 , what is the longest possible perimeter of the triangle?

1 Answer
Dec 11, 2017

Longest possible perimeter of the triangle is 32.8348

Explanation:

Given are the two angles (5pi)/12 and (3pi)/8 and the length 12

The remaining angle:

= pi - (((5pi)/12) + (3pi)/8) = (5pi)/24

I am assuming that length AB (8) is opposite the smallest angle

a/ sin A = b / sin B = c / sin C

8 / sin ((5pi)/24) = b / sin ((5pi)/12) = c / sin ((3pi)/8)

b = (8 * sin ((5pi)/12)) / sin ((5pi)/24) = 12.6937

c = (8*sin ((3pi)/8)) / sin ((5pi)/24) = 12.1411

Longest possible perimeter of the triangle is = (a + b + c) / 2 =( 8 + 12.6937 + 12.1411) = 32.8348#