Question

o is the centre of the circle and ab is the chord if od perpendicular ab find radius of the circle

Answer 1

in triangle oad
oa is radius
${oa}^{2} = {ad}^{2} + {od}^{2} \\ oa = \sqrt{ {ad}^{2} + {od}^{2} } \\ radius = \sqrt{ { \frac{ab}{4} }^{2} + {od}^{2} }$