Maths(F.3)

Q3 Because of the formula of the curved surface area is (pi)r^2(degree)/360

Q3a Let the larger cone raduis be r , smaller be s
(pi)r^2(degree)/360 : (pi)s^2(degree)/360 = 49 : 9
r:s = 7:3

Q3b It's indepentant on height
the ratio is 1:1

Q3c Because of the formula of the volume of cones is (pi)r^3/3
using 3a
the volume ratio is (pi)r^3/3:(pi)s^3/3
=(pi)r^3/3:(pi)(3r/7)^3/3
=7^3:3^3
=343:27

Q3d Because of the formula of the circumferences is 2(pi)r
it is same ratio to 3a
=7:3

Area(s) = 9:49

(a) 3:7
(b) 3:7
(c) 3:7
(d) 3:7