Question

Two opposite sides of a parallelogram each have a length of `4`. If one corner of the parallelogram has an angle of `(2 pi)/3` and the parallelogram's area is `60`, how long are the other two sides?

Answer 1

`=17.32`

Explanation:

Area `=ab sin theta` where `a=4`; `theta=2pi/3` and we have to find `b=?`
so
`60=4bsin(2pi/3)`
or
`bsin120=60/4`
or
`bsin120=15`
or
`b(0.866)=15`
or
`b=15/0.866`
or
`b=17.32`