Odpowiedź:
a = 5, b = 5, c = 6
l = 3π
l = 2πr
2πr = 3π
r = [tex]\frac{3}{2}[/tex]
P = [tex]\frac{a + b + c}{2}[/tex] × r
P = [tex]\frac{5+5+6}2}[/tex] × [tex]\frac{3}{2}[/tex] = [tex]\frac{16}{2}[/tex] × [tex]\frac{3}{2}[/tex] = [tex]\frac{48}{4}[/tex] = 12
