Areas of Cones and Others

Okay so heres the problem we did in class in case you dont have it. We needed to fine the surface area for it. The formula for surface area is:

S= 2B + ph

All you have to do is take the numbers you already have and plug them into the formula.

Then.... 

Cylinders:

If you want to find the surface area of a cylinder, you use the formula that has been circled in yellow. It tells you what is needed to find the base and perimeter. 

And...

Spheres:

 The formula to find the surface area of a sphere is:            

And when you want the formula for a hemisphere, its easy to figure out. You cut the circle in half. Then, since you cut it, you added another circle (like a face) to it. It looks like, 

So, since you have half the cirlce, you divide the original formula in half. But, you have to add that new "face" in, so add one more area of a circle to that. You end up with,

And lastly...

Cones:

The surface area for a cone is, and the l means slant height if you dont have that.              

Theres also the Frustum of a cone. It looks like....

To find its surface area really isnt that difficult. All it is is

When the letters are big, it means from the big circle, and when they are small, it means the little circle.

I think thats about it, sorry if some pictures are a little confusing.

And just for fun, i lost the game :]

Kristy