Formulas for Angles in Circles Formed by Radii, Chords, Tangents, Secants Formulas for Working with Angles in Circles (Intercepted arcs are arcs "cut off" or "lying between" the sides of the specified angles.)There are basically five circle formulas that you need to remember:1. Central Angle: A central angle is an angle formed by two intersecting radii such that its … [Read more...] about Formulas for Angles in Circles Formed by Radii, Chords, Tangents, Secants