Answer:
![30^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/high-school/g45d27fv58mtenk6bi8ebnmylcqt522qwc.png)
Explanation:
According to the given information:
Minor arc = 150°
Major arc = 360°-150°=210°
Since angle made by tangents is equal to the half of the difference between the major and the minor arcs made by them.
Let x be the viewing angle (angle made by tangents):
Then,
![x=(1)/(2)(\text{Major arc -Minor arc})\\\\\Rightarrow\ x=(210^(\circ)-150^(\circ))/(2)\\\\\Rightarrow\ x=(60^(\circ))/(2)\\\\\Rightarrow\ x=30^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/middle-school/alab2fpt2a123n89yicctggm7z3rxnekvz.png)
Hence, the viewing angle should be used=
![30^(\circ)](https://img.qammunity.org/2020/formulas/mathematics/high-school/g45d27fv58mtenk6bi8ebnmylcqt522qwc.png)