27+15+3 describe how you used addition properties?

Issof claims that the scale factor is 1/2. which statement about his claim is correct

True or false look at the picture pls : /

Find the exact value of each of the following. in each case, show your work and explain the steps you take to find the value. (a) sin 17π/6 (b) tan 13π/4 (c) sec 11π/3