Luas lingkaran 1,54 dm2 Ditanya diameter lingkaran?

==> 1, 54 dm2 = 1,54 × 100 = 154 cm2
==> r = AKAR Luas/ 22/7
=AKAR 154 / 22 / 7
= AKAR 49 = 7
diameter = 2 x r = 2 x 7 = 14 cm

Luas Lingkaran = πr²
1.54 dm³ = 22/7 x r²
1.54 dm³ x 7 = 22r²
10.78 dm³ = 22r²
r² = 10.78 : 22
r² = 0.49
r  = √0.49
r  = 0.7 dm
diameter = 2r
= 2 x 0.7 
= 1.4 dm = 14 cm