Answer:
Trigonometry is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies.
Step-by-step explanation:
The first one because it’s (13(31)
Hello :
cos60 = cos(-60)=0.5
I believe it's 199,000 to the nearest 1,000 and
200,000 to the nearest 10,000