Luas suatu lingkaran 254,34 cm².panjang jari-jarinya adalah.. A.7cm B.8cm C.9cm D.11cm

Luas lingkaran
= π × r × r
= 254,34 cm2

Panjang jari jari
= √254,34 ÷ π
= √254,34 ÷ 3,14
= √254,34 × 100/314
= √81
= 9 cm

πr^2=254,34. 3,14xr^2=254,34 r^2=254,34:3,14=81 √81=9 cm.jadi jawabanya C.9 cm