Question: What is the length of an arc of a circle with a radius of 10 cm that subtends an angle of 90 degrees at the center?

Options:

1. 5π cm
2. 10π cm
3. 15π cm
4. 20π cm

Correct Answer: 5π cm

Solution:

Arc length = (θ/360) * 2πr = (90/360) * 2π(10) = 5π cm.