Question

Apabila Luas alas =A dan Luas selimut kerucut =S, serta diketahui S-A=28cm²,dan S+A=336cm².Maka jari-jari alas kerucut adalah...........?

Answer 1

S-A=28cm²
S+A=336
----------------- -
-2A = -108
A = 54

s - a = 28
s - 54 = 28
s = 82

A = π . r²
54 =3,14 . r²
r² = 17,19
r=√17,19
r = 4,1