Two corners of a triangle have angles of π6 and π12. If one side of the triangle has a length of 8, what is the longest possible perimeter of the triangle?

1 Answer
Jan 10, 2017

45.314cm

Explanation:

The three angles for triangle are π6,π12and34π

To get the longest perimeter, the shortest length shall reflex to the smallest angle.
Let say that the other lengths are b reflex to angle π6 and c reflex to angle 34π while a=8 reflex to angle π12

therefore
asinA=bsinB=csinC

bsin(π6)=8sin(π12)

b=8sin(π12)sin(π6)
b=80.25880.5
b=15.456

csin(3π4)=8sin(π12)

c=8sin(π12)sin(3π4)
c=80.25880.7071
c=21.858

The longest possible perimeter = a+b+c
=8+15.456+21.858
=45.314cm