Odpowiedź:
z tw. Pitagorasa
a² + b² = c²
9² + 12² = c² |NL| = 15cm
81 + 144 = c²
pierwiastek 225 = c
c = 15
z tw. Pitagorasa
b² = c² - a²
b² = 17² - 15²
b² = 289 - 225 |KN| = 8cm
b = pierwiastek 64
b = 8
Ob = 17+8+9+12 = 46cm
____
P1 = a*h/2 = 9*12/2 = 9*6 = 54cm²
P2 = 8*15/2 = 4*15 = 60cm²
P = P1 + P2 = 54 + 60 = 114cm²