a]
a = 2 cm, b = 4 cm
c² = 2² + 4²
c² = 4 + 16
c² = 20
c = √20
c = 2√5 cm
Ob = 2 + 4 + 2√5 = 2(3 + √5) cm
b]
a = 4 cm, b = 8 cm
c² = 4² + 8²
c² = 16 + 64
c² = 80
c = √80
c = 4√5
Ob = 4 + 6 + 4√5 = 2(5 + 2√5) cm
c]
a = 7 cm, b = 24 cm
c² = 7² + 24²
c² = 49 + 576
c² = 625
c = √625
c = 25 cm
Ob = 7 + 24 + 25 = 56 cm