physics
posted by Jane on .
Four vectors, each of magnitude 89 m, lie along the sides of a parallelogram. The angle between vector A and B
is 77◦.
A
89 m
C
89 m
B
89 m
D
89 m
What is the magnitude of the vector sum of the four vectors?
Answer in units of m
I got 346.8757431m, but that's not right....can anyone explain how to do this correcty? Thank you in advance :)

nevermind!! i figured it out!