Surface Area Of A Right Circular Cone
Chapter Name : Surface Areas And Volumes |
Sub Topic Code : 104_09_13_04_01 |
Topic Name : Surface Area Of A Right Circular Cone |
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Sub Topic Name : Surface Area Of A Right Circular Cone |
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Introduction
• Surface area is the outside area that a multi-dimensional body has. • A pyramid shaped solid that has circular base and one vertex is called a cone. • In this section we derive surface area of circular cone.
Pre-Requisites:
• Knowledge of squares, rectangles, and circles. • Knowledge of area and perimeter.
Activity:
You will observe by finding surface area of cone we can cut number of wrappers from sheet.
Real Life Question:
Funnels in chemistry lab are made out of glass. Estimate the amount of glass needed to make the funnel.
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Surface Area | Area outside multi-dimensional body. |
| Pyramid | A pyramid has triangular sides which meet at one point called vertex. |
| Triangle | A figure with three sides and three angles. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Ice cream cone | Take a large rectangular sheet and find out how many wrappers of cone shape can be made to cover ice cream cone. |
Real life uses :
Cone shape is used to making funnels which are used in chemistry labs, fish nets, lampshades.
Places to visit :
Look for objects in your house which have cone shape?
Practical examples around us
| Examples | Explainations |
|---|---|
| How much paint is required to paint traffic cone? Traffic cone is plastic object shaped like cone which is put on road to prevent traffic from driving or stopping somewhere. | To know how much paint is required to color traffic cone we need to figure out the surface area of cone. For this we need to have base, slant height and height, radius of traffic cone. |
What you learn in Theory:
Surface area of cone is sum of the area of its faces. Cone is made up of circle and a triangle. To find one dimension of triangle we calculate circumference of circle.
What you learn in Practice:
We need to find surface area of right circular cone to like to determine how much material is required to make a cone shape lampshade.