hitunglah Lucas lingkarang jika panjang jari jari a) 7cm b) 10,5 c) 20cm

a.) r = 7 cm

L = πr²
L = 22/7 × 7 × 7
L = 22 × 7
L = 154 cm²

b.) r = 10,5 cm

L = πr²
L = 3,14 × 10,5 × 10,5
L = 3,14 × 110,25
L = 346,185 cm²

c.) r = 20 cm

L = πr²
L = 3,14 × 20 × 20
L = 3,14 × 400
L = 1256 cm²

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a. luas=π×r×r
r=7
22/7×7×7=22×7=154cm2

b.r=10,5
π=3,14

luas=3,14×10,5×10,5=346,185cm2

c.r=20
π=3,14

luas=3,14×20×20=62,8×20=1256cm2