Question

1 mark for review
the figure gives four points and some corresponding rays in the $xy$-plane. which of the following is true?
a angle $cob$ is in standard position with initial ray $ob$ and terminal ray $oc$.
b angle $cob$ is in standard position with initial ray $oc$ and terminal ray $ob$.
c angle $dob$ is in standard position with initial ray $ob$ and terminal ray $od$
d angle $dob$ is in standard position with initial ray $od$ and terminal ray $ob$.

Explanation:

An angle in standard position has its initial ray along the positive x-axis.

• For option A/B: Ray OC is on the positive x-axis. Angle COB has initial ray OC (positive x-axis) and terminal ray OB, so only option B fits this definition for ∠COB.
• For option C/D: ∠DOB cannot be in standard position as neither OD nor OB is on the positive x-axis as an initial ray, so C/D are invalid.

Answer:

B. Angle COB is in standard position with initial ray OC and terminal ray OB.