Tolong dong dijawab yang bener

→ P.busur :
= 72/360 . phi . d
= 1/5 . 22/7 . 28
= 1/5 . 22 . 4
= 88/5
= 17,6cm

→ Keliling :
= 17,6 + 14 + 14
= 17,6 + 28
= 45,6cm