## alainabbyboo22 3 years ago can someone help me please ? If AD = 8 cm and AC = 24.5 cm, calculate the length of AB. A. 16 cm B. 15 cm C. 30.63 cm D. 14 cm

1. alainabbyboo22

2. alainabbyboo22

do you know this ?

3. jim_thompson5910

4. waterineyes

Liked it..

5. alainabbyboo22

i just still don't get this .

6. waterineyes

Theorem says : $tangent^2 = Secant \cdot Chord$

7. waterineyes

I.e : $AB^2 = AD \cdot AC$ Just plug in the values..

8. jim_thompson5910

according to theorem 3 on that page b*c = a^2 In this context, if AB = x, AD = 8 and AC = 24.5, then (AD)*(AC) = (AB)^2 8*24.5 = x^2 Keep going to solve for x

9. alainabbyboo22

38416 . that is what i got cause i did 8*24.5 which equals 196 , then 196^2 and that gives me 38416 .

10. jim_thompson5910

you take the square root of 196

11. jim_thompson5910

this will give you a smaller number (than 196)

12. alainabbyboo22

14 !!

13. alainabbyboo22

thanks for helping me out on this (: i was lost !

14. jim_thompson5910

yw