sec(151 degrees) = -1.143
In order to find it on a calculator, remember that the secant is 1/cosine.
As long as your calculator does cosines, you're all set.
You cannot because you do not know what R is.
Using my calculator, I get 15.748 to the nearest thousandth.
27.000
89.000
.510
57.290
0.510
0.510
55.000
0.8192
72.000
48.000