Question

Kerucut volume 20 cm³. Diameter kerucut diperbesar 3 kali dan tinggi 2 kali.
Berapakah volume kerucut sekarang?

Answer 1

V1 = 20 cm kubik
1/3 × π × (r)^2 × t = 20
1/3 × π × (d/2)^2 × t = 20
1/3 × π × (d^2/4) × t = 20

V2 katanya diameter = 3×d ; tinggi = 2xt

V2 = 1/3 × π× (3d/2)^2 × (2t)
V2 = 1/3 × π × 9d^2 / 4 × 2t
V2 = 1/3 × π × [ 9 × (d^2/4) × 2 × t ]
V2 = 9 x 2 [ 1/3 × π × (d^2/4) × t ]
V2 = 18 × [ 20 ]
= 360 cm kubik