Find side b, angle theta, and angle alpha in the parallelogram in the picture below:
The answers should end up being a = 15 (given), b= 16.96, c = 25 (given), d = 20 (given), theta = 77.2 degrees, alpha = 102.8 degrees.
It is a different problem then before. I used the Law Of Cosines with sides a, d, and c, but didn't get the correct angle, even when I divided it by 2.
I also tried the properties of sin, cos, and tan. ...but to no avail.
|dw:1385099892141:dw| use this right triangle