Given:
Triangle LJK.
LJ = 89 in, LK = 28 in and m∠L = 42°
To find:
The length of missing side JK.
Solution:
LJ = k = 89
LK = j = 28
JK = l = ?
Using law of cosine:
Substitute the given values.
Taking square root on both sides.
The length of the missing side is 70.7 in.