a) L = (2π·36·100)/360 = 20π
L = (2πR·u)/360°
b) L = (2π·15·120)/360 = 10π
c) L =(2π·18·240) /360 = 24π
d) L = (2π·10·72)/360 = 4π
[tex]a. \: 2 \times 36 \times \pi = 72\pi \\ b. \: 2 \times 15 \times \pi = 30\pi \\ c \: . \: 2 \times 18 \times \pi = 26\pi \\ d. \: 2 \times 10 \times \pi = 20\pi[/tex]
