Question

Two opposite sides of a parallelogram each have a length of `3`. If one corner of the parallelogram has an angle of `(2 pi)/3` and the parallelogram's area is `15`, how long are the other two sides?

Answer 1

`b=5.77`

Explanation:

Area of the parallelogram is `=ab sin theta` where `a=3` is the side and `theta=(2pi)/3` and we have to find `b=?`
Therefore
Area`=15=3b sin((2pi)/3)`
or
`bsin((2pi)/3)=15/3`
or
`b(0.866)=5`
or
`b=5/0.866`
or
`b=5.77`