I fata I---I---I
II fata I---I
III fata I---I---I---I
IV fata I---I---I+19 Suma lor este 395
Notam segmentul I----I cu x
I+II+III+IV=395
2x+x+3x+2x+19=395
8x=395-19
8x=376
x=47
I fata = 2x=2·47=94 ilustrate
II fata = x = 47 ilustrate
III fata = 3x = 3·47=141 ilustrate
IV fata = 2x+19=2·47+19=94+19=113 ilustrate