Respuesta :

8828
The answer is 15 because to the the lenght of the missing number you have to use the Pythagorean Theorem.So first you have to use c^2=a^2 +b^2.
25^2=20^2 + b^2 then 625=400 + b^2. 625-400= 225. So what equals 225. The answer is 15. Hope this helps