Vectors forming a parallelogram

[shiri]

The vectors 39.0 cm at 15.0° and 23.0 cm at 68.0° both start from the origin. Both angles are measured counterclockwise from the x axis. The vectors form two sides of a parallelogram.

a) Find the area of the parallelogram.
716cm^2

b) Find the length of its longer diagonal.

For b) is this question looking for the unknown length?

**update**
I found the answer

 

[marcusl]

The wording you posted is odd since both diagonals of a parallelogram are equal. ARe you sure you copied the problem correctly?

 

[ogb p]

for b) to be 50.5 cm based on the given information and using the law of cosines to find the length of the third side of the parallelogram.