Question

Q. A line l intersects two concentric circles (circles with same
center) on points A, B, C and D (See figure)
If AD=18 cm and BC=8 cm then find AB. Center of circle is O.​ (Please give me answer I mark as brilliant.)

Answer 1

given,

AD = 18

BC = 8

so,

AD - BC = 18 - 8 = 10

so AB + CD = 10

AB = 5