Question 887414
The diameters of the bases of two cones are epual.the ratio of their slant heights is 5:4 if curved surface  of the smaller cone is 400cm2 then find the curved surface of the bigger cone.
Solution  let Curved surface area of cone Is X cm^2
Let radius of cone are r1 and r2
r1:r2=1:1  (given)
let slant height are L1 and L2 
L1:L2=5:4 (1)
curved surface area of cone =pie rL
ratio of curves surface are of cone = pie r L1/pie r L2
ratio of curved surface area =L1/L2
L1:L2=X:400  from (1)
5/4=X/400
4X= 2000
X=2000/4
X=500 Cm^2
curves surface area of cone  500 cm^2