i keep coming to the answer 4 but its actually G

http://prntscr.com/l6tg8c

how?..

I think anwer is G. 6 units long

IM SORRY it is G lol..

ok i prove it below!

\(AD=AB + BD \)

so \(AB = 30 - 20 =10 \)

and \(AB = AC + CD \)

so \(CD = 30 - 16 = 14 \)

Finally \(AD = AB + BC + CD \)

so \(BC = 30 - 10 - 14 = 6 \)

so \(BC = 6\)

Thank you !! i had to reload the page to see the answer

very much appreciated!

You're wellcome!

AD =30, AC =16

AD - AC =30 -16 =14 - the length of CD

But BD = 20, so:

BD - CD =BC

20 - 14 = 6 - the length of BC!!, or "G".

[AD - AC] = [30 - 16 ] = 14 = CD

[BD - CD ] = [20 - 14] = 6 = BC