Poti folosi principiul de asemare intr un triunghi sau Thales.
DF=AB-AD-BF=24-12-4=12-4=8
Folosim teorema lui Thales:
DE || BC
AD/AB=AE/AC=12/24=1/2=AE/30 => AE=15
Iar teorema lui Thales:
FG||BC
AF/AB=12+8/24=20/24=5/6=AG/AC=AG/30 =>AG=25 =>EG=25-15=10
GC=AC-AG=30-25=5