. Find radian measure of an angle of $90^{\circ}$. Enter the radian to be between 0 and
(Enter an exact answer. Use symbolic notation and fractions where needed.)
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Answer

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Answer

Final Answer: The radian measure of an angle of $90^{\circ}$ is $\boxed{\frac{\pi}{2}}$.

Steps

Step 1 ：Given an angle of 90 degrees, we are asked to find its radian measure.

Step 2 ：We know that $1^{\circ} = \frac{\pi}{180}$ radians.

Step 3 ：So, to convert 90 degrees into radians, we multiply 90 by $\frac{\pi}{180}$.

Step 4 ：This gives us a radian measure of $\frac{\pi}{2}$.

Step 5 ：Final Answer: The radian measure of an angle of $90^{\circ}$ is $\boxed{\frac{\pi}{2}}$.