[medonet1]

Tan x = m/ab>>>>>(1)

2(<<< and also tan x = ab/3m
from 1 and 2 , then
m / ab = ab / 3m
ab^2 = 3m^2
then ab= m square root of 3
then tan x =m/m square root of 3
tan x = 1 / square root of 3
then x =30 degrees