If an angle is formed by a $270°$ clockwise rotation from the positive x-axis, what is its measure in standard position?

• A. $-90°$
• B. $90°$
• C. $-270°$
• D. $270°$

Answer: (C)

Verified step by step guidance

1. Understand that the standard position of an angle is measured counterclockwise from the positive x-axis.
2. Recognize that a 270° clockwise rotation is equivalent to rotating in the negative direction by 270°, so the angle can be expressed as -270°.
3. Recall that angles coterminal with a given angle differ by full rotations of 360°, so you can add or subtract 360° to find an equivalent angle between 0° and 360°.
4. Add 360° to -270° to find the positive coterminal angle: \(-270^\circ + 360^\circ = 90^\circ\).
5. Conclude that the angle in standard position can be expressed as either \(-270^\circ\) or \$90^\circ$, depending on the context.