Question

Tolong ya
1. Jari jari alas sebuah kerucut 5cm dan luas selimutnya 65 phi cm persegi. Volume keruaucut adl ..... cm persegi
a. 60 phi b . 65 phi c. 100 phi d. 156 phi

Answer 1

S = 13 . v = 1/3 × L × t . v = 1/3 × 78,5 × 12 . v = 314 cm3. v = 100 phi . (C)

Answer 2

Lselimut = x r x s
65           = phi X 5 x s
s              = 65/ 5
                 = 13
t = 12 cm
Vk = 1/3 x x r x r x t
     = 1/3 x phi x 5 x 5 x 12
     =  phi x 25 x 4
     = phi x 100
     = 100 phi