Question

In the figure, AD is tangent to the circle. AB=a, BC=b, AC=c. b=?

Answer 1

@perl

Answer 2

@ParthKohli

Answer 3

Ever heard of the tangent secant theorem?

Answer 4

AD*AD = AB*AC

Answer 5

AC = (a + b)

Answer 6

yes but ive done that and it doesn't help

Answer 7

maybe its just my mistake @ParthKohli

Answer 8

@ganeshie8 do u have a method?

Answer 9

i would use tangent secant theorem
http://www.mathwarehouse.com/geometry/circle/images/secant-tangent-sides/secant-tangent-side-picture.gif

Answer 10

Why is AC=c given , but AD=c marked in the diagram?

Answer 11

assuming the diagram is the right one.

c^2 = a*(a+b)

c^2 = a^2 + a*b

b = (c^2 - a^2) / a