1. A radian is the angle that subtends an arc.

2. We can determine the perceived angle which the rainbow subtends as follows.

3. So a radian -- one radian -- is the angle that subtends an arc that's the length of the radius.

4. How do we find the relationship between psi 1 and the central angle that subtends this same arc?

5. A Bracteole is a small bract on a flower stem.A Bracteole is a small leaf-like structure which subtends a flower or inflorescence

6. In particular, every inscribed angle that subtends a diameter is a right angle (since the central angle is 180 degrees).

7. an illuminated ring target whose outer diameter, D, subtends an angle of η minutes of arc at a point situated at x metres (Figure #a); or

8. an illuminated ring target whose outer diameter, D, subtends an angle of η minutes of arc at a point situated at x metres (Figure 11a); or