3.
notam ipotenuza cu a
notam catetele cu c si b
Atriunghi =bxc/2
Asemicercurilor
π(a/2)²/2=a²π/8
π(b/2)²/2=b²π/8
π(c/2)²/2=c²π/8
Afigurii hasurate =bxc/2+b²π/8+c²π/8-a²π/8=bxc/2+π/8(b²+c²-a²)
dar a²=b²+c²
deci
bxc/2+π/8(b²+c²-a²)=bxc/2(adica aria triunghiului)
