Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
The slant height of a frustum of a cone is $4\ cm$ and the perimeter of its circular ends are $18\ cm$ and $6\ cm$. Find the curved surface area of the frustum.
Given: The slant height of a frustum of a cone is $4\ cm$ and the perimeter of its circular ends are $18\ cm$ and $6\ cm$.
To do: To find the curved surface area of the frustum.
Solution:
As given, $l=4\ cm$
Circumference of a circular end $=18\ cm$
$⇒2\pi r_1=18$
$⇒\pi\times r_1=\frac{18}{2}=9\ ...............................( 1)$
Circumference of other circular end $=6\ cm$
$⇒2\pi r_2=6$
$⇒\pi r_2=\frac{6}{2}=3\ .................................( 2)$
Adding $( 1)$ and $( 2)$
Curved surface area$=\pi(r_1+r_2)l$
$=( 9+3)\times4$
$=48\ cm^2$.
Updated on: 10-Oct-2022
39 Views
Advertisements