c2 = a2 + b2
c2 = 142 + 122
= 196 + 144
= 340
c = √340
= √4 * √85
= 2√85
x^2 + 12^2 = 14^2
x^2 = 196 - 144 = 52
x = sqrt(52) = 2 sqrt(13)m