volume sebuah kerucut=616cm .jika diameter kerucut=14cm tentukan luas permulaan kerucut

jawab
V kerucut = 616
d= 14
r = 7

V = 616
1/3 π r² t = 616
(22/7)(7²) t = 3( 616)
154 t = 3(616)
t = 3(616)/(154)
t = 12

s = √ (t²+r²) = √(12²+ 7²)
s = √193

Luas = π r² ( r + s)
L = 22/7 (7²)  ( 7 + √193)
L = 154 ( 7 + √193)