help me please
 

hi
i am new member here and i need any genuis man to answer to my question

you can see the question here

http://i13.tinypic.com/4koedcn.jpg

any one can answer to the question number three

i need the answer quickly

:notice i write my post in english because my Windows didn't contain arabic language (system errors))

i wait the answer

http://img215.imageshack.us/img215/6783/untitlednh1.jpg
من خلال النسبة والتناسب نجد ان
أ : ب : جـ = جا أ : جا ب : جاجـ = 21: 14: 13
وباضافة ثابت وتطبيق موضوع المحيط يمكن ايجاد قيمة الثابت
بالتوفيق للجميع

i can't understand any thing master

please reanswer the question in detail