Two corners of a triangle have angles of (3 pi )/ 8 and ( pi ) / 2 . If one side of the triangle has a length of 7 , what is the longest possible perimeter of the triangle?

1 Answer
Dec 20, 2017

Longest possible perimeter of the triangle is 42.1914

Explanation:

Given triangle is a right angle triangle as one of the angles is pi/2

Three angles are pi/2, (3pi)/8, pi/8

To get the longest perimeter, the side of length 7 should correspond to angle pi8 (smallest angle).

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

7/sin (pi/8) = b/sin ((3pi)/8) =c/sin (pi/2)

b = (7 * sin ((3pi)/8)) / (sin (pi/8)) = 16.8995

c =( 7 * sin (pi/2)) / sin (pi/8) = 18.2919

Longest possible perimeter = (a + b + c) = 7 + 16.8995 + 18.2919 = 42.1914