Tolong dijawab pakai cara yang lengkap​

1. L = pi r² = 22/7 *28*28

= 22*28*4 = 2464

2. L = 3/4*pi*r²

L = 3/4*3.14*20*20

= 3.14*20*15= 942

3. L = 72/360*pi*r²

= 72/360*22/7*35*35

= 1/5*22/7*35*35

= 22*5*7 = 770