Surface Area of Cones

Today we had a look at the surface area of a cone. This can be broken into two parts;

1. The area of the circular base. 
2. The area of the curved and sloped section. 

The following diagram breaks these two pieces down and shows the formula for finding the area of each, then adds these together to come up with the total surface area of the cone. 

So what this formula shows is that all you need to find the surface area of a cone is the radius (r) and the slant height (s). So for example, the surface area of the following cone (assuming the measurements are in cm) would be found like; 

You should new be able to do most if the work on the 3rd page of the second worksheet on measurement. Work through this at home. 

If you do have any questions on the topic, feel free to comment on this post, or email or chat to me in person.