Tolong dong pls jawab ini tapi pakai cara pls banget yg bantu semoga makin pintar Amin

panjang busur = sudut/360° x 2πr

1. panjang busur = 90/360 x 2 x 22/7 x 7
= 2,75

2. panjang busur = 60/360 x 2 x 22/7 x 21
= 5,5

3. 88 = 120/360 x 2 x 22/7 x r
88 = 44/21 r
r = 88 x 21/44
r = 42

4. 31,4 = a/360 x 2 x 3,14 x 100
31,4 = 314/180 a
a = 31,4 x 180/314
a = 18°

5. 1256 = 72/360 x 2 x 3,14 x r
1256 = 6,28/5 r
r = 1256 x 5/6,28
r = 1000