Mohon dibantu yaa penting banget ???

Nomer 1
bagian a
k = (2 x p) + kllg 1 lingkaran
k = (2 x 16) + ( π . d)
k = 32 + 22/7 , 14
k = 32 + 44
k = 76
bagian b
k = kllg 1/4 link + (2 x lurus)
k = (1/4 . π.d) + ( 2. 21)
k = (1/4.22/7. 42) + 42
k = 33 + 42
k = 75

nomer 2
panjang lintasan = k . n putaran
keliling = pjg lintasan : n
keliling = 7920 : 12000
keliling = 0,66 m
keliling = 66 cn

keliling = π. d

66 = 22/7 . d
d = 66/(22/7)
d = 21

nomer 3
k = 2 . π . r
k = 2 . 3,14 . 6000
k = 37680 km

nomer 4
panjang lintasan
= keliling . n putaran
= π.d . n
= 3,14 . 60 . 2
= 376,8 m

n putaran = jarak : keliling
n = 900 : (3,14 . 60)
n = 4,7 kali

nomer 5
luas jalan = lingk besar – lingk kcl
L =(22/7.42.42) – (3,14.40.40)
L = 520 m2
biaya
= 520 x 20.000
= 10. 400.000