50 kali luas lingkaran A (d=8 cm) akan sama dengan…..kali luas lingkaran B (d=20 cm)
50 x 4² = B x 10²
50 x 16 = B x 100
800 = B x 100
B = 800/100
B = 8
50 La = x Lb
La = phi r^2
= 16phi
Lb = phi (10)^2
= 100phi
50 (16) = x 100
16 = 2x
X = 4 kali