Answer :

Given: The slant height of the frustum of a cone is 4 cm and the perimeters of its circular ends are 18 cm and 6 cm.

To find: the curved surface of the frustum.

Solution:


For the given frustum:




Slant height, l = 4 cm

Perimeter of its circular ends = 18 cm and 6 cm

Let radius of larger and shorter ends be 'r' and 'R' resp., then

Perimeter of larger circular end = 2 π r = 18 cm

π r = 9

Similarly, 2π R = 6

π R = 3

Curved surface of the frustum = (π r +π R) × l

= (9 + 3) × 4

= 12 × 4

= 48 cm2

Rate this question :

How useful is this solution?
We strive to provide quality solutions. Please rate us to serve you better.
Related Videos
Sphere and HemisphereSphere and HemisphereSphere and Hemisphere16 mins
Right Circular CylinderRight Circular CylinderRight Circular Cylinder45 mins
Cube and CuboidCube and CuboidCube and Cuboid41 mins
Right Circular Cone And FrustumRight Circular Cone And FrustumRight Circular Cone And Frustum43 mins
Heights and Distances-IHeights and Distances-IHeights and Distances-I45 mins
History - Concept and QuestionsHistory - Concept and QuestionsHistory - Concept and Questions57 mins
Resources and Development RevisionResources and Development RevisionResources and Development Revision28 mins
Corrosion: Types, Pros and ConsCorrosion: Types, Pros and ConsCorrosion: Types, Pros and Cons41 mins
Revision on Substitution and  Elimination MethodRevision on Substitution and  Elimination MethodRevision on Substitution and Elimination Method44 mins
Economics - Concept and QuestionsEconomics - Concept and QuestionsEconomics - Concept and Questions59 mins
Try our Mini CourseMaster Important Topics in 7 DaysLearn from IITians, NITians, Doctors & Academic Experts
Dedicated counsellor for each student
24X7 Doubt Resolution
Daily Report Card
Detailed Performance Evaluation
caricature
view all courses