Question

Two concentric circles of radii 5 cm and 3.0 cm have a line segment

inside the bigger circle in such a way that this line segment is chord of

bigger circle and tangent to smalier, then find length of this line segment.​

Answer 1

given two concentric circles with centre o and radii 5 cm and 3 cm

AB is the chord

(ACO ) =90 (angle between tangents and radius)

in triangle ACO ,by pythagoras theorem

OA ²=OC²+AC²

5²=3²+AC²

25=9+AC²

25-9=AC²

AC²=16

AC=16

AC =4cm.