Given a central angle of $90°$, which of the following is its measure in radians?

• A. $\frac{2\pi }{3}$
• B. $\frac{\pi }{2}$
• C. $1$
• D. $\pi$

Answer: (B)

Verified step by step guidance

1. Recall the formula to convert degrees to radians: \(\text{radians} = \text{degrees} \times \frac{\pi}{180}\).
2. Substitute the given central angle of 90 degrees into the formula: \$90 \times \frac{\pi}{180}$.
3. Simplify the fraction \(\frac{90}{180}\) to its lowest terms.
4. Multiply the simplified fraction by \(\pi\) to express the angle in radians.
5. Compare the resulting expression with the given options to identify the correct radian measure.